Abstract: Objective To explore the clinical effect of addition and subtraction of traditional Chinese medicine adjuvant therapy on threatened abortion and its effects on immune, inflammatory response and reproductive endocrine hormones. Methods A total of 82 threatened abortion patients treated in Gynecology Department of Jiaxing Hospital of Traditional Chinese Medicine from June 2018 to April 2019 were selected as the study subjects, they were randomly divided into observation group(n=41) and control group(n=41). The control group was treated with progesterone injection, while the observation group was treated with traditional Chinese medicine on the basis of the control group. The clinical total effective rate, interleukin-2(IL-2), interleukin-10(IL-10), interferon-γ(IFN-γ), tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), human chorionic gonadotropin(β-HCG), progesterone(P), and estradiol(E₂) levels were compared between the two groups. Results The clinical total effective rate of the observation group was 95.12%(39/41), which was significantly higher than that of the control group(78.05%, 32/41, P<0.05). The levels of IL-2 and IFN-γ in the observation group were significantly lower than those in the control group(all P<0.05), and the levels of IL-10 in the observation group were significantly higher than those in the control group(P<0.05). The level of TNF-α in the observation group was significantly lower than that before treatment and in the control group(all P<0.05), and the level of IL-6 in the observation group was significantly lower than that before treatment(P<0.05), but there was no significant difference between the two groups(P>0.05). The levels of β-HCG and E2 in the observation group were significantly higher than those before treatment and in the control group(all P<0.05). The levels of P in the observation group were significantly higher than that before treatment(P<0.05), but there was no significant difference between the two groups(P>0.05). Conclusion The treatment of threatened abortion by adding or subtracting traditional Chinese medicine can improve the immune ability of patients, reduce the occurrence of inflammatory reaction and improve the level of endocrine.