Reducing food losses are becoming an important mean of saving resources and increasing food supply. Based on the survey data of 1196 households in 23 provinces, this paper measured the corn storage losses of different sizes, and used the Fractional Logit model to study the causes and determinates of corn storage losses in different sizes. The result shows, with the increase of scale, the corn storage loss rate decreased first and then increased, and the corn storage loss rate of middle-scale farmers was the lowest. The empirical analysis result shows that expand the corn storage scale and adopt advanced corn storage facilities can reduce the corn storage loss of different sizes. In addition, rodent damage will increase corn storage losses for large and medium-sized farmers. Compared with other measures, physical control is positively related to corn storage losses for large and small farmers. Increase the land scale will increase the corn storage loss of large and small-scale farmers; the variety is positively related to the corn storage loss of large and medium-sized farmers.