Abstract: Objective: To detect the levels of platelet parameters and soluble P-selectin in the patients with chronic spontaneous urticaria (CSU). Methods: The levels of platelet parameters, and soluble P-selectin in 120 patients and 40 healthy controls were detected and the relationship between these parameters and autoimmune serum test (ASST) and urticaria severity score (USS) was analyzed. Results: The levels of mean platelet volume (MPV)，platelet distribution width (PDW) and soluble P-selectin were 11.23±1.36fl, 13.41±2.26fl and 74.16±20.32 ng/mL in the patients，which were significantly higher than those in controls group (9.38±1.24fl, 11.17±2.51fl and 32.14±8.37 ng/mL, respectively). The level of platelet count in CSU group was (176.16±41.05×109/L), which was significantly lower than that in controls (227.35±42.33 ×109/L). There was a significant positive correlation between USS and P-selectin levels in the patients and the correlation between USS and MPV in the patients with positive ASST was also significantly positive. Conclusion: The levels of MPV, PDW and soluble P-selectin were increased in the patients with CSU and were correlated to the disease severity. The platelets are activated in the patients with CSU.

Key words: urticaria, mean platelet volume, P-selectin