To probe the diagnostic value of transvaginal color Doppler ultrasonography plus serum β-human chorionic gonadotropin (β-HCG) dynamic monitoring in intrauterine residue after medical abortion.In total, 200 pregnant women undergoing medical abortion in our institution from January 2017 to December 2019 were picked, and assigned to either group A (n = 75, with residue) or group B (n = 125, without residue). We detected serum β-HCG, progesterone (P), follicle stimulating estrogen (FSH) levels and ultrasonic indicators endometrial thickness (ET), peak systolic velocity (PSV), resistance index (RI) values, dissected correlation of indicators using logistic linear regression analysis, and prospected the diagnostic value of relevant indicators in intrauterine residue after medical abortion utilizingreceiver operating characteristic curve.At 7 days after abortion (T3), total vaginal bleeding and visual analogue scalescore in group A were saliently higher in contrast to group B ( P < .05). At 72 hours after abortion (T2) and T3, serum β-HCG, P and FSH levels declined strikingly in both groups, but group B held plainly higher decrease rate than group A ( P HC.05). At T3, ET and PSV levels in both groups considerably waned, whereas RI levels notedly waxed, and group B owned markedly higher decrease/increase than group A ( P wa.05). At T3, serum β-HCG in group A possessed positive association with serum P, FSH, intrauterine ET, PSV levels separately ( P HC.05), whereas negative link with RI levels ( P , .05). The specificity and sensitivity of β-HCG, P, FSH, β-HCG/ET, β-HCG/PSV and β-HCG/RI in the diagnosis of intrauterine residue after medical abortion were high ( P < .05).Serum β-HCG dynamic monitoring plus transvaginal color Doppler ultrasonography is of great value in diagnosing intrauterine residue after medical abortion. Serum β-HCG, P, FSH levels can be combined with the results of intrauterine ET, PSV, RI values, so as to boost the diagnostic accuracy of the intrauterine residue after medical abortion.