Objective To examine the effect of acupoint injection at Sanyinjiao（ SP6） with Danshen Injection on primary dysmenorrhea. Methods Ninety primary dysmenorrhea patients were randomized into three groups with 30 cases in each group. Point injection of Danshen group was treated with Danshen Injection in bilateral Sanyinjiao（ SP6） point

1 ml each side

once in a menstrual cycle. Point injection of saline group was given normal saline in bilateral Sanyinjiao（ SP6） point

1 ml each side

once in a menstrual cycle. Oral dropping pill group was given oral Yuanhu Zhitong Dropping Pill（ 元胡止痛滴丸）

30 pills each time

3 times each day for 3 days. The treatment started on the 1 st day of menstruation in menstrual cycle

1 menstrual cycle as a course

totally treating for 3 courses. The degree of dysmenorrhea was evaluated by visual analog scale（ VAS） before treatment

after treatment（ at the end of the 3 rd menstrual cycle） and during follow-up（ after stopping treatment for 3 menstrual cycles）. Results Compared before treatment

the pain score in the point injection of Danshen group and the oral dropping pill group decreased after treatment and during follow-up（ P < 0. 05）; while the pain score in the point injection of saline group had no significant change at different time point（ P > 0. 05）. Compared with the point injection of saline group at the same time

the pain score in the point injection of Danshen group and the oral dropping pill group decreased after treatment and during follow-up（ P < 0. 01）. During follow-up

the pain score in the point injection of Danshen group was lower than that in the oral dropping pill group（ P < 0. 05）. Conclusion SP6 Danshen injection treating primary dysmenorrhea was effective and the long-term effect seemed good.