Abstract Objective This study aimed to illustrate the copper status of diminished ovarian reserve in Chinese women, especially the effects of copper, ceruloplasmin, non‐ceruloplasmin‐bound copper (NCC) and CuZn superoxide dismutase (SOD1). Methods This case–control, cross‐sectional investigation included women with diminished ovarian reserve (DOR group, n = 35) and matched normal ovarian reserve (NOR group, n = 35). The serum levels of copper, ceruloplasmin, NCC, SOD1, follicle‐stimulating hormone, luteinizing hormone, estradiol, testosterone, and anti‐Müllerian hormone were tested and analyzed. Results The serum copper concentrations (60.88%), NCC (54.75%) and SOD1 (54.75%) in the DOR group were significantly higher than those in the NOR group (all P < 0.001), and the concentrations of the three markers were higher in most subgroups ( P < 0.001). The correlation analysis verified the correlation between copper status and impaired ovarian function. Additionally, linear regression analysis showed that NCC and SOD1 levels were negatively correlated with anti‐Müllerian hormone ( P < 0.05 or 0.001). Conclusion Our exploration found significant increases in copper, NCC and SOD1 levels in DOR and suggests a possible link. Copper status is expected to serve as the predictive marker for DOR.