DX是Distant eXchange简写。业余无线电DX活动的原本是更好地研究和利用电离层传播条件而进行的与远方业余电台的双向交流活动。后发展为一种具体表现为猎奇和追求PILEUP的活动，大家试图联络分布尽可能泛，数量尽可能多的业余电台，从而，DX活动成为业余无线电一个重要分支。1935年，美国人设计了一种旨在推动业余无线电活动的“游戏”，叫“DX Century Club”。按照规则，全世界被分成许多“DXCC分区(DXCC country)”，一个真正的政治概念的国家是一个“DXCC分区”。该国家拥有主权的并与之相隔225海里以上岛屿也可算一个“DXCC分区”。

分区

前缀 国家(地区)

1A0 SMO Malta 马耳他SMO

1S Spratly Island 南威岛（南沙群岛 目前被越南政府控制）

3A Monaco 摩纳哥

3B6 Agalega & St Brandon 阿加莱加群岛&圣布兰登群岛

3B8 Mauritius 毛里求斯

3B9 Rodrigues Island 罗得里格斯岛（毛里求斯岛屿，位于西印度洋马斯克林群岛东部）

3C Equatorial Guinea 赤道几内亚

3C0 Pagalu 安诺本岛

3D2 Fiji 斐济

3D2/C Conway Reef 康威礁

3D2/R Rotuma 罗图马岛

3DA Swaziland 斯威士兰

3V Tunisia 突尼斯

3W Vietnam 越南

3X Guinea 几内亚

3Y/B Bouvet 布维岛

3Y/P Peter I 彼得一世岛

4J Azerbaijan 阿塞拜疆

4J1 Malyj Vysotskij Island 马利 维索茨克（俄罗斯西北）

4K2 Franz Josef Land 法兰士约瑟夫地群岛

4L Georgia 格鲁吉亚

4S Sri Lanka 斯里兰卡

4U/IT ITU Geneva 日内瓦（国际电信联盟）

4U/UN UN Headquarters 联合国总部

4W1 East Timor (UNTAET) 东帝汶（联合国东帝汶过渡行政当局）

4X Israel 以色列

5A Libya 利比亚

5B Cyprus 塞浦路斯

5H Tanzania 坦桑尼亚

5N Nigeria 尼日利亚

5R Madagascar 马达加斯加岛

5T Mauritania 毛里塔尼亚

5U Niger 尼日尔

5V Togo 多哥

5W Western Samoa 西萨摩亚

5X Uganda 乌干达

5Z Kenya 肯尼亚

6W Senegal 塞内加尔

6Y Jamaica 牙买加

7O Yemen 也门

7P Lesotho 莱索托

7Q Malawi 马拉维

7X Algeria 阿尔及利亚

8P Barbados 巴巴多斯

8Q Maldives 马尔代夫

8R Guyana 圭亚那

9A Croatia 克罗地亚

9G Ghana 加纳

9H Malta 马耳他

9J Zambia 赞比亚

9K Kuwait 科威特

9L Sierra Leone

9M2 West Malaysia

9M6 East Malaysia

9N Nepal

9Q Zaire

9U Burundi

9V Singapore

9X Rwanda

9Y Trinidad & Tobago

A2 Botswana

A3 Tonga

A4 Oman

A5 Bhutan

A6 United Arab Emirates

A7 Qatar

A9 Bahrain

AP Pakistan

BS7 Scarborough Reef

BV Taiwan

BV9 Pratas Island

BY China

C2 Nauru

C3 Andorra

C5 Gambia

C6 Bahamas

C9 Mozambique

CE Chile

CE0A Easter Island

CE0X San Felix

CE0Z Juan Fernandez

CN Morocco

CO Cuba

CP Bolivia

CT Portugal

CT3 Madeira Island

CU Azores

CX Uruguay

CY0 Sable Island

CY9 St Paul Island

D2 Angola

D4 Cape Verde

D6 Comoros

DL Fed. Rep. of Germany

DU Philippines

E3 Eritrea

E4 Palestine

EA Spain

EA6 Balearic Island

EA8 Canary Island

EA9 Ceuta & Melilla

EI Ireland

EK Armenia

EL Liberia

EM Ukraine

EP Iran

ER Moldovia

ES Estonia

ET Ethiopia

EU Belarus

EX Kyrgyzstan

EY Tajikistan

EZ Turkmenistan

F France

FG Guadeloupe

FH Mayotte

FK New Caledonia

FK/C Chesterfield Is.

FM Martinique

FO French Polynesia

FO/A Austral Islands

FO/C Clipperton Island

FO/M Marquesas Islands

FP St Pierre & Miquelon

FR Reunion

FR/G Glorioso Island

FR/J Juan de Nova; Europa

FR/T Tromelin

FS St Martin

FT/W Crozet

FT/X Kerguelen Island

FT/Z Amsterdam & St Paul Island

FW Wallis & Futuna Island

FY French Guiana

G England

GD Isle of Man

GI Northern Ireland

GJ Jersey

GM Scotland

GU Guernsey

GW Wales

H4 Solomon Island

H40 Temotu Isl

HA Hungary

HB Switzerland

HB0 Liechtenstein

HC Ecuador

HC8 Galapagos Island

HH Haiti

HI Dominican Rep

HK Colombia

HK0 San Andres & Providencia

HK0/M Malpelo Island

HL South Korea

HP Panama

HR Honduras

HS Thailand

HV Vatican

HZ Saudi Arabia

I Italy

IS Sardinia

J2 Djibouti

J3 Grenada

J5 Guinea-Bissau

J6 St Lucia

J7 Dominica

J8 St Vincent

JA Japan

JD/M Minami Torishima

JD/O Ogasawara

JT Mongolia

JW Svalbard

JX Jan Mayen

JY Jordan

K United States

KC4 Antarctica

KC6 Belau

KG4 Guantanamo Bay

KH0 Mariana Island

KH1 Baker & Howland Island

KH2 Guam

KH3 Johnston Island

KH4 Midway Island

KH5 Palmyra; Jarvis Island

KH5K Kingman Reef

KH6 Hawaii

KH7 Kure Island

KH8 American Samoa

KH9 Wake Island

KL7 Alaska

KP1 Navassa Island

KP2 Virgin Islands

KP4 Puerto Rico

KP5 Desecheo Island

LA Norway

LU Argentina

LX Luxembourg

LY Lithuania

LZ Bulgaria

OA Peru

OD Lebanon

OE Austria

OH Finland

OH0 Aland Island

OJ0 Market Reef

OK Czech Republic

OM Slovak Republic

ON Belgium

OX Greenland

OY Faroe Islands

OZ Denmark

P2 Papua New Guinea

P4 Aruba

P5 North Korea

PA Netherlands

PJ2 Netherland Antilles

PJ5 St Maarten,Saba,St Eustatius

PY Brazil

PY0F Fernando de Noronha

PY0P St Peter & St Paul Rocks

PY0T Trindade & Martim Vaz Island

PZ Surinam

S0 Western Sahara

S2 Bangladesh

S5 Slovenia

S7 Seychelles

S9 Sao Tome & Principe

SM Sweden

SP Poland

ST Sudan

SU Egypt

SV Greece

SV5 Dodecanese

SV9 Crete

SY Mt Athos

T2 Tuvalu

T30 West Kiribati

T31 Central Kiribati

T32 East Kiribati

T33 Banaba Island

T5 Somalia

T7 San Marino

T9 Bosnia-Herzegovina

TA Turkey

TF Iceland

TG Guatemala

TI Costa Rica

TI9 Cocos Island

TJ Cameroon

TK Corsica

TL Central African Rep

TN Congo

TR Gabon

TT Chad

TU Ivory Coast

TY Benin

TZ Mali

UA European Russia

UA2 Kaliningradsk

UA9 Asiatic Russia

UK Uzbekistan

UN Kazakhstan

V2 Antigua; Barbuda

V3 Belize

V4 St Kitts & Nevis

V5 Namibia

V6 Micronesia

V7 Marshall Islands

V8 Brunei

VE Canada

VK Australia

VK0/H Heard Island

VK0/M Macquarie Island

VK9C Cocos-Keeling Island

VK9L Lord Howe Island

VK9M Mellish Reef

VK9N Norfolk Island

VK9X Christmas Island

VK9Z Willis Island

VP2E Anguilla

VP2M Montserrat

VP2V British Virgin Islands

VP5 Turks & Caicos Islands

VP6 Pitcairn Island

VP6/D Duice Island

VP8 Falkland Islands

VP8/G South Georgia Island

VP8/H South Shetland Island

VP8/O South Orkney Island

VP8/S South Sandwich Island

VP9 Bermuda

VQ9 Chagos

VR2 Hong Kong

VU India

VU7/A Andaman & Nicobar Island

VU7/L Lacshadweep Isl

XE Mexico

XF4 Revilla Gigedo

XT Burkina Faso

XU Cambodia

XW Laos

XX9 Macao

XZ Myanmar (Burma)

YA Afghanistan

YB Indonesia

YI Iraq

YJ Vanuatu

YK Syria

YL Latvia

YN Nicaragua

YO Romania

YS El Salvador

YU Yugoslavia

YV Venezuela

YV0 Aves Island

Z2 Zimbabwe

Z3 Macedonia

ZA Albania

ZB Gibraltar

ZC4 UK Sov. Bases on Cyprus

ZD7 St Helena

ZD8 Ascension Island

ZD9 Tristan da Cunha & Goug

ZF Cayman Islands

ZK1/N North Cook Island

ZK1/S South Cook Island

ZK2 Niue

ZK3 Tokelau Island

ZL New Zealand

ZL7 Chatham Islands

ZL8 Kermadec Island

ZL9 Auckland & Campbell Island

ZP Paraguay

ZS South Africa

ZS8 Pr Edward & Marion Island