To evaluate the efficacy and safety of Choudongning (CDN)capsule in children with Tourette's syndrome of spleen deficiency and phlegm accumulation through a randomized double-blind three-arm controlled phase Ⅲ study in 588 patients from 8 hospitals. The included patients were randomly divided into test group, positive control group and placebo group at the ratio of 3∶1∶1. Patients in the test group orally took CDN capsules and simulated Tiapridal tablets; the patients in positive control group took Tiapridal tablets and simulated CDN capsules; whereas the patients in placebo group orally took the simulated agents of the above two drugs. The treatment course was 6 weeks for three groups. The global grading rates, YGTSS scores and its factor scores, the degree of social function damage, as well as traditional Chinese medicine syndrome efficacy were evaluated as the outcome measures on efficacy. The AEs/ADRs, vital signs and laboratory testing were observed as outcome measures on safety. The total effective rate of YGTSS was 75.92% in the test group, 72.65% in the positive control group, and 37.29% in the placebo group. Non inferiority test stands between the test group and the positive control group, and they were superior to placebo group in efficacy with statistical difference. Significant difference had also been found among the 3 groups in YGTSS tics score, motor tics score, vocal tics, degree of social function damage and traditional Chinese medicine syndrome efficacy. During the study, there were 5 (1.42%)ADRs in the test group, 10 (8.55%)in the positive control group and 3 (2.54%)in the placebo group. The incidence of ADRs in the test group was lower than that in the positive control group, with statistical difference. It is clear to say that CDN capsule can effectively treat the Tourette's syndrome of spleen deficiency and phlegm accumulation. Its efficacy is not inferior to the commonly used Tiapridal tablets, with even less adverse reactions, so it has clinical application value.