Objective To explore the value of serum progesterone level in the early diagnosis of ectopie pregnancy. Method Serum progesterone levels were measured prospectively in 36 patients with ectapic pregnancy and 30 women with normal intrauterine pregnancy. Results The serum progesterone level in ectopic pregnancy [(5.12± 3.98) μg/L] was lower than that in normal intrauterine pregnancy [(25.23±6.81) μg/L]. Recommended 11 μg/L as the cutoff point of progesterone concentrations in diagnosis of ectopie pregnancy, the sensitivity rate was 91.7%(33/36), specificity rate was 93.3%(28/30),missed diagnosis rate was 8.3% (3/36) in the diagnosis of eetopie pregnancy. Conclusion The serum progesterone detection can be considered as an early diagnostic method of eetopie pregnancy because it can be measured easily and quickly.