Objective: This study aimed to evaluation that predicts clinical outcomes after cryopreserved thawing embryo transfer (T-ET) using initial maternal serum human chorionic gonadotrophin levels. Methods: Cryopreserved thawing embryo transfer cycles (n = 248) were collected between 1 January 2014 and 30 December 2018 with positive HCG values and retrospectively analysed by receiver operating characteristic curves to predict clinical pregnancy, ongoing pregnancy and delivery. At 7 days post-T-ET, the serum human chorionic gonadotropin (HCG) was measured. The main predicted outcome was ongoing pregnancy. Results: A total of 175 patients with cryopreserved T-ET were included. Among them, 44 patients achieved a successful live birth. Initial serum HCG titer was elevated in 107 women. Among them, 30 ultimately had a chemical pregnancy, while 14 experienced a clinical abortion. The area under curves for clinical pregnancy and live birth prediction were 0.95 and 0.91, respectively; corresponding cut-off values were 22.8 mIU/mL and 26.5 mIU/mL. Conclusion: Lower initial maternal serum HCG levels indicated poorer clinical outcomes and live birth rate.