【Abstract】 Objective To find the impact of women patients weight on outcome in vitro fertilization and embryo transfer cycles. Methods A retrospective study was carrid out on the long protocol IVF/ICSI cycles in our reproductive center from January，2011 to December，2011．The study included 764 patients .And the patients were stratified according to the body mass index(BMI) : normal with BMI ≤ 24.0 kg/m2 (n=606), overweight and obese with BMI > 24.0 kg/m2 (n=158), compared the basic clinical factors, the major factors in cycles treatment and the last pregnancy outcome. Results The factors including ages of both men and women, the period of infertility, and basic sexual hormonal including FSH and LH levels were similar in two different groups of cycles(P > 0.05). Also, there were no differences between the two groups about the duration of using gonadotropin, the number of oocytes, fertility rate，embryo quality rate， on the day of HCG injection intimal thickness, the average number of embryo transfer ，implantation rate，clinical pregnancy rate,parturition rate,the abortion ratio and ectopic pregnancy rate (P > 0.05). However, there are more differences in gonadot ropin dose(P <0.05). Conclusions　Overweight and obese patients require a higher gonadot ropin dose in ovulation induction，but has no influence on the outcome of the IVF(ICSI) cycles.