Abstract: Objective To assess the value of monitoring serum human chorionic gonadotropin β-subunit (β-HCG) level changes in early diagnosis of ectopic pregnancy. Methods Totalling 106 cases of ectopic pregnancy and 69 cases of threatened abortion were included in the study. Blood samples were collected to examine β-HCG levels, which was repeated 2-3 days later. Results Initial serum β-HCG levels of the women with ectopic pregnancy and different were significantly lower than those in women with threatened abortion (P<0.05), and the increatment rate of serum β-HCG in the former was also significantly lower (P<0.05). Conclusion Compared with single-time serum β-HCG detection, dynamic monitoring of serum β-HCG provides more important and reliable evidence for early diagnosis of ectopic pregnancy. Transvaginal ultrasonogrophy and in should also be considered in the clinical analysis.