<正> Objective: To study whether stem cell factor （SCF） and gonadotropin work synergisticly in super-ovulation stimulation of an in-vitro fertilization and embryo transfer （IVF-ET） program. Methods: Total cycles of 30 IVF-ET patients with regular menstrual period were studied. The same superovulation regimen was employed. Enzyme-linked immunosorbent assay （ELISA） and radioimmunoassay （RIA） were used to determine the levels of SCF

follicular-stimulating hormone （FSH） and luteinizing hormone （LH） in follicu-lar fluid （FF） during oocyte pick-up （OPU） and in serum before and after superovulation. Results: FF-SCF levels were significantly higher in high and moderate reactive groups [（564±64） ng · L-1

（532±55） ng · L-1

respectively] than that in low reactive group [（352±78） ng · L-1

P<0. 01]; FF-FSH levels were significantly different in three groups [（23. 7±5. 7） U · L-1

（24. 5±8. 9） U · L-1

and （15. 4±4.1） U · L-1

respectively

P<0. 05]. FF-LH levels were lower in low reactive group (33. 0±7.