Abstract Objectives This study aimed to investigate the influence of hypoxia on angiogenesis in a 3D gel, with co‐culturing adipose‐derived stromal cells ( ASC s) and endothelial cells ( EC s). Materials and methods ASC s from green fluorescent protein‐labeled mice and EC s from red fluorescent protein‐labeled mice were co‐cultured in 3D collagen gels at 1:1 ratio, in normal and hypoxic oxygen conditions, and morphology of angiogenesis was observed using confocal laser scanning microscopy. To discover changes in growth factors between monoculture ASC s and EC s, transwell co‐cultures of ASC s and EC s were applied. Semi‐quantitative PCR was performed to explore mRNA expression of growth factors. Results Enhanced angiogenesis was observed in 3D gels implanted with 1:1 mixture of ASC s and EC s after 7 days hypoxia. Genes including VEGFA / B , EGF ‐1 , HIF ‐1a , IGF ‐1 , PDGF , TGF ‐β1 and BMP ‐2/4 in EC s, both monoculture and co‐culture, were significantly enhanced after being cultured under hypoxia. In comparison, genes VEGFA /B , EGF ‐1 , HIF ‐1 a, TGF ‐β1 and BMP ‐2 in ASC s increased. In all, factors VEGFA /B, EGF ‐1, HIF ‐1a, TGF ‐β 1 and BMP ‐2 increased in both ASC s and EC s after being cultured in hypoxia no matter whether as monoculture or co‐culture. Conclusions Co‐culture of ASC s and EC s at 1:1 ratio in a 3D gel under hypoxia promoted angiogenesis. Those growth factors which were increased in both ASC s and EC s, indicate that VEGFA /B , EGF ‐1, HIF ‐1a, TGF ‐β1 and BMP ‐2 might be responsible for enhancement in angiogenesis triggered by hypoxia.