Intravitreal anti-vascular endothelial growth factor (VEGF) agents have revolutionized the treatment of retinopathy of prematurity (ROP); however, there are concerns regarding the potential systemic complications caused by those treatments. This study aimed to determine the serum concentrations of cytokines in infants with ROP and to evaluate the changes in serum VEGF concentrations after intravitreal conbercept (IVC). Sixty infants with ROP treated with IVC 0.25 mg were included. Blood samples were collected before treatment as well as 1 week and 4 weeks after treatment. Serum levels of 45 types of cytokines were measured by a multiplex bead assay. We observed that IVC 0.25 mg in ROP patients suppressed the circulating levels of VEGF-A and VEGF-D as of 1 week after injection, and these growth factor levels returned to baseline at 4 weeks. No significant differences were observed in the serum levels of the other cytokines between baseline and 1 or 4 weeks after IVC.