To observe the relation between the pain threshold and the therapeutic effects of acupuncture for sciatica. Methods: 90 sciatica patients were equally divided at random into the following 3 groups: a warming acupuncture group treated with the needles wanned by bing moxa,a west medicine group administered Nimesulide tablets and a point-injection group with Anisodamine injected. The pain threshold was tested before treatment and after the first,second and third treatment courses. Results: The warming acupuncture therapy showed better therapeutic effects than the other two groups with significant differences in the change of pain threshold and the improvement of clinical symptoms and signs (P<0.01). Conclusion:Acupuncture can relieve the symptoms of sciatica with the increase of pain threshold.