The recombinant glycoprotein, LBD-005 (Lucky R & D Center, Biotechnology)stimulates the growth of stem cells and activates the development of the hematopoietic cell in a similar manner to the naturally occurring GM-CSF. This test was conducted to investigate if LBD-005 had any effect on fertility in male and female rats. Sprague-Dawley rats(88 of each sex) bred at KRICT, were dosed subcutaneously, at a volume of 2ml/kg body weight with LBD-005 at 0, 250, 500 or 1, 000mg/kg body weight. The male rats were dosed, from 6 weeks of asge, for 60 days prior to mating.