Objective To investigate the impacts of body mass index (BMI) and age on in vitro fertilization-embryo transfer (IVF) and intracytoplasmic sperm injection (ICSI) treatment in infertile patients without polycystic ovary syndrome (PCOS). Methods A retrospective study of 1426 patients during Jun. 2001 - Nov. 2009 was carried out. Multiple regression was used to analyze the effects of BMI (low weight: BMI＜18.5 kg/m2, normal weight:BMI 18.5-23.99 kg/m2 and over weight-obesity: BMI≥24 kg/m2) and age (young: 20-34 years old, eld: 35-45 years old) on controlled ovarian stimulation (COH)[including:dose and duration of Gn, E2 level on day of human chorionic gonadotropin (HCG) administration, number of oocytes collected and full-grown follicles ],number of fertilization, cleavage, two-pronucleus, normal embryos and cryopreserved embryos and clinical pregnancy outcome. Results ( 1 ) Gn dose for the patients whose age were 35 and the above,had a positive correlation with age (P＜0.001), 12.70% of the total variation of Gn dose was related to age (standardized partial regression coefficient was 0.343). (2) Estradiol level on day of HCG administration had a negative correlation with BMI in overweight-obesity patients, and so were the patients whose age were 35 and above (P value respectively lower than 0.037 and 0.018). 0.80% of the total variation of estradiol (HCG day) is related to age and overweight-obesity while age took greater proportion (standardized partial regression coefficients were 0.066 and 0.058 respectively). (3)For older patients, age appeared to have negative relationships with duration of Gn and number of oocytes collected, full-grown follicles, fertilization, cleavage, two-pronucleus, normal embryos and cryopreserved embryos (P＜0.05). (4)Compared to young-normal weight patients, the odds ratio of pregnancy in eld-low weight and eld-overweight-obesity patients were 0.482 and 0.529 (P＜0.05)respectively. Conclusion Age, but not the BMI, had significant effects on IVF/ICSI treatment. It seems that factors as losing weight before IVF or ICSI treatment effective in reducing the dose of Gn.