To determine whether topical application of trimix extracts of Mylabris phalerata Pall., Arisaematis Rhizoma and Pinelliae Rhizoma Ternata lead to affects on the hair growth activity in C57BL/6N mice. To examine the hair growth activity of the extracts of Mylabris phalerata Pall., Arisaematis Rhizoma and Pinelliae Rhizoma Ternata gross, microscopic, and immunohistochemical method were performed. In order to examine the mRNA expression of hair growth related substance, RT-PCR method was performed. Experimental group I on day 14, The most extensive hair growth activity was observed in whole skin area of all the mice whose hair had been clipped. Brdu immunoreactive cells of all the experimental groups were more heavily stained in epidermis, bulge, outer root sheath, inner root sheath, subcutaneous tissue, hair bulb and cutaneous trunci muscles than that of control group on day 12 of hair growing cycle in C57BL/6N mice. VEGF immunoreactive density of all the experimental groups was more heavily stained in epidermis, bulge and cutaneous trunci muscles than that of control group on day 12. FGF and c-kit immunoreactive cells of all the experimental groups were heavily stained in epidermis, outer root sheath, inner root sheath and cutaneous trunci muscles on day 12. PKC-$alpha$ immunoreactive density of all the experimental groups was mildly stained in epidermis and cutaneous trunci muscles than that of control group on day 12. On day 12, the expression of bFGF (138%, 119%, 120%), VEGF (146%, 144%, 133%), IGF-1 (165%, 141%, 119%) and PLI (121%, 116%, 123&) in each experimental groups was more increased than that of control group. On day 16, The expression of IGF-1 (126%, 149%, 151%) in all the experimental group was more increased than that of control group (100%). The expression of bFGF (92%, 94%) and VEGF (101%, 97%), PL1 (102%, 109%) in all the experimental group was more decreased than that of experimental group I, II on day 12. But the expression of bFGF (109%) and VEGF (127%), and PL1 (105%) in each experimental group III was more increased than that of control group (100%). These experiments suggest that trimix extracts of Mylabris phalerata pall., Arisaematis Rhizoma and Pinelliae Rhizoma Ternata may stimulate the topical hair growth activity and its experimental group I can be useful for treatment of alopecia areata.