OBJECTIVE: To evaluate the significant effects of blood concentration monitoring of cyclosporine A（ CsA） in the treatment of psoriasis.METHODS: Data of 161 patients with psoriasis treated with CsA were collected in the Hospital for Skin Diseases

Chinese Academy of Medical Sciences and Peking Union Medical College from 2018 to2020.The effects of gender

age

dose

drug combination and blood concentration of CsA were compared and analyzed.RESULTS: The blood concentration of CsA was monitored for 288 case-times in 161 patients

with an average of 1.79 times/case.The average blood concentration of CsA was（ 123.23 ± 49.72） ng/ml.The average daily dose of CsA in female patients was significantly higher than that in male patients

and the difference was statistically significant（ P =0.013）.There was no statistical significance in the average blood concentration of CsA between male and female patients（ P>0.05）.The difference of blood concentration of CsA in patients of different ages was extremely significant（ P<0.001）

and the difference in daily dose was also statistically significant（ P < 0.05）.There was no significant difference in blood concentration of CsA in patients with different types of psoriasis（ P>0.05）.The blood concentration of CsA was influenced by drug combination of macrolides

calcium antagonist and salviae miltiorrhizae.CONCLUSIONS: Age

drug combination and food may affect the blood concentration of CsA.Clinically

it is necessary to strengthen the blood concentration monitoring

and formulate individualized drug administration program based on the monitoring results to improve the safety and effectiveness of clinical administration.