A feeding trial was conducted to evaluate the effect of live yeast culture Saccharomyces cerevisiae (SC) and Spirulina platensis (SP) on the growth performance and serum biochemical parameters in rabbits. Forty, male New Zealand white rabbits, aged 5-6 weeks, were studied in 4 groups. The groups; I. Control (basal diet), II. SC (added 3 g/kg diet), III. SP (added 5% of the diet), IV. SC and SP (added 3 g/kg SC and 5% SP of the diet), respectively. The experiment lasted for 90 days. Blood samples were obtained by ear venipuncture on the 90th day. Also final body weight, total weight gain, total feed intake and feed conversion ratio were evaluated at the each month of the 90th day trial. There were no significant differences occurred in growth performances and biochemical parameters, but serum globulin value decreased and albumin globulin ratio increased in SP and SC+SP groups (P<0.05). More studies would be necessary to elucidate the effects of supplementing spirulina on growth and determine the optimum dietary concentration in animals.