This paper focuses on the recent findings of sexual reproduction in monogonont rotifers,which account for the main bulk of phylum Rotifera.Generally,they act as one of the major groups of primary consumers in freshwater ecosystem.Thus,studies on population dynamics and their mechanisms of monogonont rotifers may provide important data to both theoretical and applied research on freshwater ecosystems.As a group with parthenogenetic life history,sexual reproductive strategy in monogonont rotifers may profoundly affect their population dynamics and evolution.This review summarized several aspects of sexual reproduction in the monogonont rotifers,such as the mechanism,pheromones,models,influence factors,and particularly,empirical evidences.More specifically,we emphasized three models about their sexual reproduction patterns: "bang-bang"model,intermediate mictic ratios model and no-delaying mixis model.Then we summarized the exogenous and endogenous factors that affect sexual reproduction.The major exogenous factors include the concentration and type of food,temperature,salinity and special bacteria,while the major endogenous factors include the maternal age,a transgenerational maternal effect induced by food concentration,mixis delay and some potential maternal effects.We especially highlighted the model,mechanism and empirical evidences of mixis delay,since this phenomenon existed widely and was deem to be a potential explanation for species or clones coexistence.We also gave some personal views on the relationship between sex allocation theory and sexual reproduction in the monogonont rotifers.Finally,several potential hotspots in the future study were highlighted.