Abstract: [Abstract] Objective To evaluate the clinical effect between primary radical operation and incision and drainage of the treatment on crissum abscess．Methods 84 cases of crissum abscess were randomly divided into treatment group (n=44) and control group (n=40). Patients in treatment group were received primary radical operation, patients in control group were only treated by incision and drainage. Results Compared with the control group, treatment group patients postoperative abscess recurrence rate forming the incidence of anal fistula, wound healing time significantly lower than the control group obviously(p<0.001)．Two groups were anal incontinence, anal stenosis and postoperative anal malformation, etc., were followed up for 1 year, anus function are normal．Conclusions It is suggested that primary radical operation can be primarily performed，lower the abscess recurrence and anal fistula incidence，which not only shorten treatment course，but also reduce pain of patients．Primary radical operation is a good method of crissum abscess therapy．

Key words: [key words] crissum abscess, incision and drainage, primary radical operation