Objective:To investigate the effect of extracorporeal shock wave acupoint therapy on shoulder pain and the levels of serum 5-hydroxytryptamine (5-HT) and prostaglandin E,2, (PGE,2,) in patients with shoulder periarthritis. Methods82 patients with shoulder periarthritis were randomly assigned into treatment group and control group, 41 patients in each group. The control group was treated with routine extracorporeal shock wave therapy, while the treatment group was treated with extracorporeal shock wave acupoint therapy. The treatment course was 4 weeks. The therapeutic effect was observed. Changes in VAS score of shoulder pain, shoulder range of motion as well as levels of serum 5-HT and PGE,2, were compared.  Results:①There was no drop-out during the trial. ②The total effective rate was significantly higher in the treatment group (97.56%) than in the control group (80.49%) (P,<,0.05). ③After treatment, the VAS scores of shoulder pain decreased in both groups (P,<,0.05); and the difference in the scores before and after treatment were greater in the treatment group than in the control group (P,<,0.05). ④After treatment, the shoulder range of motion increased significantly in both groups (P,<,0.05); and the difference in shoulder range of motion before and after treatment was greater in the treatment group than in the control group (P,<,0.05). ⑤After treatment, the levels of serum 5-HT and PGE,2, decreased significantly in both groups (P,<,0.05); and the differences in the levels before and after treatment were greater in the treatment group than in the control group (P,<,0.05).  Conclusion:Extracorporeal shock wave acupoint therapy is effective in patients with shoulder periarthritis as it relieves shoulder pain, increases shoulder range of motion and reduces the levels of PGE,2, and 5-HT in serum.