OBJECTIVE To investigate the effect of Shenkang Injection (SI) on hypertrophy and expressions of p21 and p27 in glomerular mesangial cells of rats cultured in high glucose fluid. METHODS Cultured rat glomerular mesangial cells were divided into 6 groups: the normal control group, mannitol-treated group, high glucose-treated group, high, middle and low dose SI treated groups. The synthesis of cell protein and DNA were determined with incorporation of 3H-TdR and 3H-Leu. The changes of p21 mRNA and expressions of p21 and p27 protein were determined by reverse transcriptase polymerase chain reaction and Western blot. RESULTS High glucose caused incorporation of 3H-TdR reduced, incorporation of 3H-Leu increased. SI could decrease incorporation of 3H-Leu, increase incorporation of 3H-TdR. Compared with the high glucose-treated group, SI could inhibit the overexpression of p2l mRNA and protein,p27 protein induced by high glucose. CONCLUSION SI could inhibit hypertrophy of glomerular mesangial cells cultured in high glucose partly through inhibiting overexpressions of p2l mRNA, p21 and p27 protein.