Spheroid-basedcelldelivery has been demonstrated as an effective strategy instemcelltherapyofcriticallimbischemia. However, massive generationofuniform-sizedspheroidsstill remains a big challenge. In addition, how spheroidsizeinfluences its therapeutic efficacy remains an open question. Herein, patterned poly(2-hydroxyethyl methacrylate) hydrogel films synthesized in situ incellculture plates are used to generate adipose-derived stromalcell(ADSC)spheroids. This method not only allowsforthe productionofuniform-sizedspheroidsbut also large-scale production (approximate to 60 000spheroidsper plate). Using this method, monodisperse ADSCspheroidswith three different sizes are generated to study spheroidsizeeffectinischemiatreatment. It is found that differentsizespheroidsexhibit different behaviors in extracellular matrix (ECM) expression and paracrine secretion. Largerspheroidsexpress more ECM proteins. Paracrine secretionofhypoxia-induced survival factors, anti-apoptotic and angiogenic factors is enhanced to a larger degree in largerspheroids. Finally, using a mouse modelofhindlimbischemia, it is demonstrated that the therapeutic efficacyofthespheroidsincreases with increasing spheroidsize. The improved therapeutic efficacy is attributed to enhanced survival and paracrine secretionoflargerspheroids, which is attributed to the higher degreeofhypoxic environmentofthesespheroids.