The purpose of this study was to investigate the effects of life stress on serum cortisol and lipid concentration in college students. Life stress levels for last 1 year were determined using a self‐administered life stress questionnaire in 406 college students. It was divided into 3 subgroups by scores distribution based on total life stress scores [the top 25%: high stress group (HSG), the low 25%: low stress group (LSG) and middle range: middle stress group (MSG)]. From 406 college students, fifty college students’ blood (high stress group: n=23, middle stress group: n=9, low stress group: n= 18) were sampled for this study. Serum cortisol level as a stress biomarker and serum triglyceride, total cholesterol and HDL‐cholesterol concentrations were measured. LDL‐cholesterol concentration and atherogenic index (AI) were calculated. Mean life stress level of HSG, MSG, LSG were 138.04 ± 36.3, 58.6 ± 8.7 and 16.3 ± 7.2, respectively. Serum cortisol level was not significantly different among 3 subgroups and there was no significant correlation between serum cortisol level and lipid concentrations. But serum HDL‐cholesterol concentration and AI were significantly different among 3 subgroups and there was significantly negative correlation between life stress level and HDL‐cholesterol concentration (p< 0.01), and there was significantly positive correlations between life stress level and AI (p< 0.01). These results suggested that high life stress level may have adverse effects on cardiovascular disease through decreasing serum HDL‐cholesterol concentration and increasing AI. Also serum cortisol level may not be a biomarker for chronic life stress.