Objective To observe the effect and safety of polysaccharide nucleic acid of Bacillus Calmette-guerin combined with compound glycyrrhizin in treatment of alopecia areata. Patients were divided into 2 groups. Methods 45 patients in treatment group were treated with polysaccharide nucleic acid of Bacillus Calmette-guerin 2mL every other day， combined with compound glycyrrhizin 50mg 3 times per day. 44 patients in the control group with were treated with compound glycyrrhizin 50mg 3 times per day. All patients were treated with Minoxidil tincture. The course lasted for twelve weeks， and adverse effects were observed between these two groups. Results After twelve weeks treatment， the total response rates of the treatment group and control group effective rates were 90.9% and 70.7%， comparision among the two group was significantly different. Conclusion Polysaccharide nucleic acid of Bacillus Calmette-guerin combined with compound glycyrrhizin in treatment of alopecia areata has a good efficiency and high safety.