This study was performed to investigate the immature development period, fecundity, emergence rate and sex ratio of Sclerodermus harmandi against different host insects, Monochamus alternatus, M. saltuarius and Psacothea hilaris. Full grown larvae and pupae of host insects were provided with foods. The mean larval period of S. harmandi female was 29.2±0.93 and 25.1±0.47 days in larvae and pupae of M. alternatus, 27.1±0.41 and 26.0±0.69 days in M. saltuarius, and 26.3±0.38 and 31.2±0.24 days in P. hilaris, respectively. S. hilaris adults were emerged at 12.9±0.2 days in female and 11.9±0.2 days in male after pupation when hosted M. alternatus pupa. Development period in male showed shorter one day than in female. Success rate of oviposition against different hosts was higher as 98.6 and 97.5% on full grown larva and pupa of M. saltuarius. Emergence rate was higher as 90.1 and 87.3% on M. saltuarius larvae and pupae. Sex ratio of emerged S. harmandi adults was approximately 10:1 (Female : Male), females showed higher emergence rate than males. The period until first oviposition after emergence in S. harmandi female was the shortest in 4.6±0.1 days on M. saltuarius pupa. When three females of S. harmandi were inoculated on M. saltuarius larva, the number of laid eggs was the highest 62.7±2.5 per female.