The aim of this study was to compare the response and their outcome of superovulation induction protocol in IVF-ET program. One hundued seventy seven infertile women were stimulated by FSH/hMG(group I, N=128), clomiphene citrate/hMG(group II, N=51), and hMG(group III, N=18) for the purpose of ovulation induction. The results were as follows; 1. The mean ages of patients were $31.9{pm}3.8$ in group I, $30.6{pm}3.3$ in group II, and $29.3{pm}2.5$ in group III. 2. The day of hCG administration was $11.1{pm}1.8$ in group I, $12.1{pm}2.0$ in group II, and $13.7{pm}6.8$ in group III. The hCG administration day of group III was significantly delayed compared with that of group I (p<0.001). 3. The terminal E2 pattern in group II was different from those of group I and III, but there was no significant difference. 4. The mean numbers of mature eggs aspirated were $5.5{pm}3.8$ in group I, $5.0{pm}3.3$ in group II, and $5.6{pm}5.4$ in group III. There was no significant differences in the mean numbers of mature eggs retrieved among the three groups. 5. The fertilization rate of eggs was significantly higher in group II (67.9%) than that of group I (52.2%)(p<0.001). 6. The cleavage rate of group I (67.0%) was significantly lower than those of group II (93.2%) and group III (95.8%) (p<0.0001). 7. The mean numbers of embryos transfered were $3.3{pm}1.4$ in group I, $3.1{pm}1.3$ in group II, and $3.2{pm}1.6$ in group III and the ET rate was 69.0% in group I, 77.3% in group II, and 100% in group III. There was significant difference in ET rate between group I and group III (p<0.005). 8. The pregnancy rates per OPU cycle or ET cycle were not significantly different among the three groups, but delivered and ongoing pregnancy rates were significantly different between group I (36.8%) and group II (p<88.8%) (p<0.05).