Beijing Subway Introduction

The Beijing Subway (simplified Chinese: 北京地铁; traditional Chinese: 北京地鐵; pinyin: Beijing ditie is an extensive underground rail system in Beijing. Presently, Subway Lines 1, 2, 4, 5, 8 (Beitucheng - South Gate of Forest Park), 10 (Bagou - Jinsong), 13, the Airport Express and the Batong Line are in service.
Subway Line 1 (Pingguoyuan - Sihui East)
Subway Batong Line (Sihui - Tuqiao)
Subway Line 2 (inner orbital; loop line underneath northern half of 2nd Ring Road)
Subway Line 3 (partially cancelled, but now in the plans again)
Subway Line 4 (Anheqiao North - Gongyixiqiao, opened on September 28, 2009; Yongfeng - Anheqiao North opening later)
Subway Line 5 (Tiantongyuan North - Songjiazhuang)
Subway Line 8 (Zhuxinzhuang - Meishuguandongjie, Stage 1 (South Gate of Forest Park - Beitucheng) presently open; construction on Stage 2 (Zhuxinzhuang - Forest Park and Beitucheng - Meishuguandongjie) started on December 8, 2007; Zhuxinzhuang - Forest Park opens 2010; rest opens 2012)
Subway Line 10 (outer orbital; Bagou - Jinsong presently open; the rest will be operational by 2012)
Subway Line 13 (Xizhimen - Huilongguan - Huoying - Dongzhimen)

Fares
All prices are unified at CNY 2.00 for unlimited mileage across unlimited transfers. The sole exception is the Airport Express; here, an extra CNY 25 ticket is required to ride the airport link. Airport Express riders cannot ride other Subway lines without paying the standard CNY 2 network fee. All lines started using simplified AFC (automatic fare collection) ticket systems.

Coverage
The Beijing Subway covers all of the extended Chang'an Avenue (Subway Line 1 and the Subway Batong Line), half of the 2nd Ring Road as well as the Xuanwumen - Qianmen - Chongwenmen region (Subway Line 2), a straight north-south stretch from Tiantongyuan through Dongsi and Dongdan through to Liujiayao and Songjiazhuang (Subway Line 5), the Olympic Green (Subway Line 8), Zhongguancun, Beitucheng West and East Roads, Shaoyaoju, Taiyanggong and the eastern 3rd Ring Road (Subway Line 10), Dazhongsi, Wudaokou, Shangdi, Huilongguan, Beiyuan, Wangjing, Shaoyaoju and Liufang (Subway Line 13), and Beijing Capital International Airport (Airport Express).

[source:eBeijing.gov.cn]