Background: Diminished ovarian reserve (DOR) contributes significantly to female infertility. Embryo quality affects pregnancy outcome. However, the factors that influence pregnancy outcomes in DOR patients are not well established. In this study, we analyzed the medical records of infertile women with DOR who underwent ART to reveal the possible correlation between clinical characteristics and embryo quality. Methods: A retrospective cohort study was conducted using 3390 medical record data on IVF cycles from Dalian Municipal Women and Children’s Medical Center (Group) from January 2015 to December 2020. The data was divided into poor-quality embryos group and high-quality embryos group according to the embryo status. We summarized the demographic and clinical characteristics (age, infertility years, infertility type, AFC, and BMI), medical history, reproductive hormone parameters (AMH, FSH, LH, PRL, and E2), and carbohydrate and lipid metabolic indexes (CHO, TG, LP, LDL, HDL, FINS, Glucose, and Hcy). To further evaluate the Hcy levels in patients with different embryo quality, we performe subgroup analysis. In order to further evaluate the Hcy levels of patients with different embryo quality, we conducted a subgroup analysis, which was divided into three subgroups: Hcy ≥15, 15> Hcy >8 and Hcy ≤8. A total of 1023patients with DOR were included in this study.Results: Of these, 483 cases were with high-quality embryos (the number of high quality embryo, number≥1), and 540 cases with poor-quality embryos (no high quality embryo, number=0). Demographic characteristics of the two groups were similar. However, the level of serum Hcy was significantly higher in the poor-quality embryo group compared with the high-quality embryo group (P < 0.05). In addition, the levels of serum AMH and PRL were statistically different between the two groups. Patients with serum Hcy ≥ 15 μmol/L were at higher risk of having poor-quality embryos (82.1%) compared to patients with serum Hcy less than 8 μmol/L (43.9%) and at 8~15 μmol/L (48.1%) (c2 =15.859, P < 0.001).Conclusion: The presented study demonstrated that high serum Hcy level is linked to poor-quality embryos. Moreover, Hcy coupled with age might be a sensitive marker for embryo quality after IVF.