The aim of this study was to determine the effect 6 weeks training and 6 weeks detraining onanthropometrical factors in non-athletes females' students in Guilan university.Thirty fivesubject were divided into three overweight(n=10;25<BMI<33); optimalweight(n=12;18<BMI<24) and control(n=13;18<BMI<30) groups.subjects’ training inexperimental group was 3 days per week: Each session of training consist of 10min warm up;20min cycling on cycle ergometer with 60-70% HRRmax and 10min cool down. Than subjectsdetrained for 6 weeks. The result of this study showed that after 6 weeks aerobic training ‚ therewas a significant weight decrease in optimal weight group ‚ also in overweight group W;BF%‚WHR and BMI were reduced significantly(p<0.05).After comparing the mean deferencechanges between groups‚ it was observed that there was a significant difference between controlgroup and over overweight group in W‚BF% and WHR between experimental and controlgroup(p<0.05).After detraining there was no significant change in groups. After Comparison themean deference changes between groups‚ it was observed that there was not a significantdifference between groups in W; BF%‚WHR; LBM; and BMI. It can be concluded that theeffect of aerobic training on anthropometrical factors in overweight group was clearer thanoptimal group. Previous research indicated that the main substrate for energy expenditure inover weight's individual in rest is fat oxidation. Because the obsess people have more BF%; soenergy expenditure in overweight group is larger than in optimal groups. However the result ofthis study showed that detraining has same effect in individual with different weight to.