Aim To investigate the role of sex hormone in development of CHD by assessing the serum level of estrogen,testosterone,the ratio of E₂/T and their relation with serum lipids in female member of myocardial infarction(MI) pedigrees. Methods Female members from eligible MI pedigrees were selected,and divided into two groups,coronary group: 21 members who suffered CHD,health group: 22 healthy members in MI pedigrees.Control group was consisted of 22 healthy volunteers from non CHD pedigrees.Serum estrogen,testosterone,and serum lipids were assayed. Results There is no difference about age,blood pressure among three groups.The level of serum estrogen of CHD members was almost as same as that of health group and control group,but the serum testosterone in coronary group was much higher than that in health group and control group.There is no difference between the latter two groups. Especially,the ratio of E₂/T in coronary group was significant lower,compared with the healthy group.Additionally,the ratio of E₂/T was positively related to HDLC,while negatively related to TC,TG,LDLC. Conclusion In MI pedigrees,the development of CHD in female members has no relation with the level of endogenous estrogen,while the level of endogenous testosterone especially the ratio of E₂/T seems to play an important role during this event through influencing the lipid metabolism.