To investigate the clinical curative effect of Guizhi decoction on chronic idiopathic urticaria, at the same time to observe the impact on matrix metalloproteinase 9 (MMP-9) and 25-hydroxyvitamin D concentrations in the peripheral blood of the patients. Methods:A total of 60 cases of patients with chronic idiopathic urticaria who visited the dermatology clinic in our hospital included in the research were randomly divided into the control group and the observation group. The control group took loratadine 10 mg/times, 1 time/day, combined with cetirizine 10 mg/times, 1 time a day. The observation group had Guizhi decoction on the basis treatment of the control group. Both of the 2 groups had treatment for 28 days. The clinical curative effects of 2 groups after treatment was observed, and enzyme-linked immunosorbent assay (ELISA) and protein immunoblot (Western Blotting) was used to observe the concentration changes of MMP-9 and 25-hydroxyvitamin D in the 2 groups before and after treatment. Results:1) The total effective rate of the observation group was 86.67%, higher than that the total effective rate 66.67% of control group. The differences were statistically significant (P<0.05). 2) 25-hydroxyvitamin D concentration in the peripheral blood of the 2 groups increased after treatment, and the increasing trend of observation group was more significant. Compared with the control group, the difference was statistically significance (P<0.05); 3) The MMP-9 concentrations of peripheral blood of the 2 groups declined after treatment compared with before the treatment, and the falling range of the observation group was higher than control group. The differences were statistically significant (P<0.05).