Take Subway Line 4 (towards Beiyuan Bridge or Tiangongyuan), Line 9 (towards National Library), or Line 16 (towards Beianhe or Wanpingcheng) to National Library Station. Exit at D and walk south along Zhongguancun South Street. Pass by the National Library Concert Hall and Kopei Computer School, and you'll reach the south entrance of the National Library in about 3 minutes.