A full-length aFGF cDNA was cloned and inserted into a T7 expression vector for heterologous expression in E. coli. For high level production of aFGF, an optimal condition for overexpression (incubation at 42 degrees C for 2 hours) and a simple purification procedure employing in vitro refolding and an affinity chromatography was established. The production yield was 40 - 50 mu g/mg of inclusion body preparation and purified aFGF showed mitogenic activity.