Objective: To investigate the effect of Composite Divitriol Infusion (CDI) in treating tinea manum and study its antimycotic action.Methods: CDI was used to treat 139 patients with tinea manum and compared with Tinea Unguium Infusion in treating 77 cases as control. The experimental study in vivo was done

and electron microscopy (EM) was used to observe the therapeutical effect of CDI.Results: Among the 139 patients of the CDI group

104 were cured

21 markedly effective

10 improved and 4 ineffective

the cure and markedly effective rate being 89.9%. The difference of effect between the CDI group and the control group was significant statistically (X 2>12.84

P < 0.005). The antimycotic action of CDI was studied in vitro. The minimum inhibitory concentration (MIC) of CDI were about 0.25% for Trichophyton rubrum and 0.5% for Trichophyton gypseum and Microsporum gypseum. Trichophyton rubrum immersed with CDI showed that the mycelia became roughened

deformed

and macroconidium became smaller under EM.Conclusion: CDI is valuable in treating tinea manum.