Frequent irrigation and high nitrogen application rates cause great nitrogen losses in vegetablefields，which can potentially be alleviated by using slow-release fertilizers such as matrix-based slow-release urea(MSU).However，littleis known about the effects of MSU in vegetable fields.The study aimed to(i)determine the effects of MSU on nitrogenleaching and ammonia volatilization；and(ii)investigate the effects of MSU on growth and nitrogen use efficiency of waterspinach(Ipomoea aquaticaForsk).A 2 -year field experiment(2016～2017)was conducted to determine the effects ofMSU on biomass，morphological and physiological traits，and nitrogen use efficiency of water spinach.Three treatmentswere control test(CK，without nitrogenapplication)，regular urea(RU)，andMSU.The nitrogen leaching and ammonia volatilization were studied with laboratoryexperiments.The results showed that compared with RUtreatment，MSUtreatment reduced nitrogen leaching(by 9.2 percentagepoints)and ammonia volatilization(by 8.7 percentagepoints)；MSUtreatment increased soil inorganic nitrogen concentration(by ≥6.7%)；MSU treatment increased leaf area(by ≥8.5%)and leaf SPAD(by ≥18.4%)；MSU treatment improved leaf net photosynthetic rate(by ≥11.1%)，stomatal conductance(by ≥14.3%)，and carboxylation efficiency(by ≥25.1%)；MSU treatment improved leaf nitrate reductase activity(by ≥11.4%)；MSU treatment increased root area(by ≥7.7%)；MSU treatment increased plant biomass(by ≥18.4%)and nitrogen apparent recovery efficiency(by ≥7.3%)；however，MSU treatment had little effects on vegetable quality(e.g.，vitamin C，crude protein，soluble sugar，and nitrate nitrogen).Overall，MSU is a promising slow -release fertilizer forproduction of vegetables such as waterspinach，due to its effects on improving plant growth and apparent recovery efficiency and reducing the risk of nitrogen loss.