hhlim was a new heart-related gene cloned from human embryonic heart whose product participated in transcriptional regulation and cell development as a kind of transcriptional factor. Over expression of hhlim gene using recombinant plasmid was sufficient to induce a greater than 1.5 fold increase in C2C12 muscle cell area compared with that untransfered with hhlim. RT-PCR and Western blot testified that transfection of hhlim into the C2C12 muscle cells could induce α-actin over expression and trigger the expression of embryonic related gene-BNP, which is related to the cell hypertrophy. hhlim-green fluorescence fusion protein in hhlim-pEGFP-C3 transfected C2C12 muscle cells was recorded with fluorescence microscopy during C2C12 muscle cell differentiation induced by horse serum. The data showed that the distribution change of green fluorescence of hhlim-GFP fusion protein from cytoplasm to nucleus was observed. Co-immunoprecipitation proved that hhlim protein exists in a manner that associates with α-actin in cytoplasm.