Abstract: Cropland scale, cropland fragmentation and other cropland resource endowment characteristics directly affect farmers' cropland input behavior. It is significant to explore the influence mechanism of those resource endowment characteristics on farmers' cropland ecological protection behaviors, in order to promote the cropland ecological protection and agricultural green transformation and upgrading. The research methods were to collect 434 valid data through a questionnaire survey of farmers in Changde City, a large agricultural city. On this basis, the effects of cropland scale and fragmentation of cropland on farmers' cropland ecological protection behaviors were empirically tested by using the Tobit model with fertilizer and pesticide application as an example. At the same time, this paper refined the cropland scale into cropland management scale and plot scale, and explored the interaction between cropland management scale, plot scale, and cropland fragmentation. The results show that: ① The deepening of the degree of cropland fragmentation will exacerbate the amount of fertilizer and pesticide applied by farmers, and promote the positive effect of cropland management scale on the amount of fertilizer and pesticide applied. This is not beneficial to the adoption of cropland ecological conservation behaviors by farmers. ② The relationship between cropland management scale and the amount of fertilizer and pesticide applied is inverted ‘U’-shaped. With the expansion of the cropland management scale, the fertilizer and pesticide application per unit sowing area of farmers shows an increasing trend, when the cropland management scale increases to a certain extent, the expansion of the cropland management scale will reduce the fertilizer and pesticide application. It is conducive to the adoption of cropland ecological protection measures by farmers. ③ The expansion of the plot scale will reduce the amount of fertilizer and pesticide applied by farmers. ④ Expansion of plot scale will weaken the positive impacts of cropland fragmentation and cropland management scale on fertilizer and pesticide application, which can in turn promote the adoption of ecological protection behaviors for cropland. In conclusion, we should actively promote the concentration of cropland, minimize the degree of cropland fragmentation, increase the plot scale, further promote the ecological protection of rural cropland, and realize the high-quality development of agriculture.