Transforming growth factor (TGF) family is well known to induce the chondrogenic differentiation of mesenchymal stem cells (MSC). However, the precise signal transduction pathways and underlying factors are not well known. Thus the present study aims to evaluate the possible role of C2 domain in the chondrogenic differentiation of human mesenchymal stem cells. To this end, 145 C2 domains in the adenovirus were individually transfected to hMSC, and morphological changes were examined. Among 145 C2 domains, C2 domain of protein kinase C eta ($PKC{eta}$) was selected as a possible chondrogenic differentiation factor for hMSC. To confirm this possibility, we treated $TGF{eta}3$, a well known chondrogenic differentiation factor of hMSC, and examined the increased-expression of glycosaminoglycan (GAG), collagen type II (COL II) as well as $PKC{eta}$ using PT-PCR, immunocytochemistry and Western blot analysis. To further evaluation of C2 domain of $PKC{eta}$, we examined morphological changes, expressions of GAG and COL II after transfection of $PKC{eta}$-C2 domain in hMSC. Overexpression of $PKC{eta}$-C2 domain induced morphological change and increased GAG and COL II expressions. The present results demonstrate that $PKC{eta}$ involves in the TGF-${eta}3$-induced chondrogenic differentiation of hMSC, and C2 domain of $PKC{eta}$ has important role in this process.