Aim To explore whether cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) affects high glucose-induced human umbilical vein endothelial cell (HUVEC) injury by targeting miR-98-5p. MethodsHUVECs were divided into control group (cultured in DMEM containing 5 mmol/L glucose), model group (cultured in DMEM containing 33.5 mmol/L glucose), model＋si-NC group, model＋si-CDKN2B-AS1 group, model＋miR-NC group, model＋miR-98-5p mimic group, model＋si-CDKN2B-AS1＋anti-miR-NC group, model＋si-CDKN2B-AS1＋anti-miR-98-5p group. The expressions of CDKN2B-AS1 and miR-98-5p in HUVEC were detected by quantitative real-time polymerase chain reaction; Signal transducer and activator of transcription 3 (STAT3) protein expression was detected by Western blot; Apoptosis was detected by flow cytometry; Superoxide dismutase (SOD), lactate dehydrogenase (LDH), malondialdehyde (MDA) kits were used to detect SOD, LDH, MDA levels. Targeted binding of miR-98-5p to CDKN2B-AS1 and STAT3 was analyzed by dual-luciferase reporter experiment. Results High glucose increased CDKN2B-AS1 and STAT3 expressions, cell apoptosis rate, LDH and MDA levels, and decreased miR-98-5p expression and SOD level in HUVEC (P＜0.05). After silencing CDKN2B-AS1 or overexpressing miR-98-5p, high glucose-induced CDKN2B-AS1 and STAT3 expressions, cell apoptosis rate, LDH and MDA levels decreased, while miR-98-5p expression and SOD level increased in HUVEC (P＜0.05). Dual-luciferase reporter experiment results showed that CDKN2B-AS1 targeted miR-98-5p and miR-98-5p targeted STAT3. Inhibition of miR-98-5p reversed the inhibitory effects of CDKN2B-AS1 silencing on high glucose-induced HUVEC apoptosis, oxidative stress, and STAT3 protein expression. Conclusion Silencing CDKN2B-AS1 suppresses high glucose-induced oxidative stress and apoptosis in HUVEC by regulating the miR-98-5p/STAT3 axis, and CDKN2B-AS1 may serve as a candidate therapeutic target for diabetes-related vascular complications.