AIM: Through studying the differences between wild-type acidic fibroblast growth factor (waFGF) with recombinant aFGF (raFGF), the biological effect of raFGF concerned with mitogenic activity was evaluated. METHODS: NIH3T3 cell line was used. Cell proliferation with MTT method was used to study the mitogenic activity. Flow cytometry was also used for detection of apoptosis, cell membrane permeability and mitochondria potential. The role of heparin sulfate (HS) on aFGF biological effect was studied at the same time in this research. RESULTS: The enhancement of raFGF on cell proliferation was significantly lower than that of waFGF. The restriction of raFGF on apoptosis and the enhancement of it on cell membrane permeability were all lower than those of waFGF significantly. The enhancement of raFGF on mitochondria potential was lower than that of waFGF significantly. The HS improved the biological effect of aFGF. CONCLUSION: The mitogenic activity of raFGF is lower than that of waFGF and raFGF has little effect on apoptosis.