On January 15, 1971, the initial line began operation on a trial basis between the Beijing railway station and . Single ride fare was set at ¥0.10 and only members of the public with credential letters from their work units could purchase tickets. The line was in length, had 10 stations and operated more than 60 train trips per day with a minimum wait time of 14 minutes. On August 15, the initial line was extended to and had 13 stations over . On November 7, the line was extended again, to Gucheng Lu, and had 16 stations over . The number of trains per day rose to 100. Overall, the line delivered 8.28 million rides in 1971, averaging 28,000 riders per day.