Abstract: The understanding of the incipient motion of cohesive sediment is a great challenge in the research of sediment incipient motion. It is recognized that cohesive forces are critical in determining the characteristics of cohesive sediment incipient motion. Based on the analysis of current research, cohesive forces are summarized in two main categories (containing six types) according to the formation mechanism, and the formation mechanism and influencing factors of the typical electric double layer force and EPS cohesive force are explored. The impact of cohesive forces on cohesive sediment incipient motion is examined in terms of two aspects, i.e. sediment stability and incipient motion modes. Based on the discussion above, it is concluded that current studies generally focus on one certain cohesive force and seldom take the interaction and comprehensive effect between cohesive forces into consideration, lacking systematicness. Moreover, most of the current research achievements based on measured data are empirical and short of quantitative relationship derived from mechanism level, suffering from a theoretical deficiency. It is suggested that the various cohesive forces should be considered comprehensively in line with the specific sedimentary environment. What's more, the formation mechanism research of cohesive forces should be concerned fundamentally, and the quantification research of cohesive forces needs more attention.