基于陕西、甘肃、山东、云南四省826户苹果户的调研数据，利用无条件分位数回归和中介效应模型实证分析了收入、社会资本对农民阶层自我定位的影响。结果表明：有45.89%的农民阶层自我定位为“上层”和“中上层”，44.07%的农民定位为“中层”，10.05%的农民定位为“中下层”和“下层”，呈“上头大，下头小”的保龄球状，高位认同占主导特征；收入对农民阶层自我定位有着显著的正向影响，且收入对阶层自我定位的系数从0.10分位点上的0.386逐步减小至0.75分位点的0.157，边际作用逐渐下降，存在“餍足效应”；社会资本及其三个维度均对阶层自我定位具有显著正向影响，且收入在社会资本促进阶层自我定位中发挥中介作用，其中收入在社会网络与阶层自我定位之间的中介效应最大，为15.47%。

Based on the survey data of 826 apple growers in four provinces of Shaanxi, Gansu, Shandong and Yunnan, the article analyzes the impact of social capital and income on the farmers’ class identification by adopting the unconditional quantile regression and mediation effect model. The results show that 45.89% of the farmers identified themselves at the upper level and upper middle level, 44.07% "middle", and 10.05% lower middle and lower,, taking the bowling ball shape of "big at the top and small at the bottom" with the dominant feature of high identity. Income has a significant positive effect on the farmers’ class identification, and the coefficient of income on their class identification gradually decreases from 0.386 at 0.10 to 0.157 at 0.75, with the gradual decline of marginal effect and the presence of "satiety effect". Social capital and its three dimensions all have a significant positive influence on the farmers’ class identification, and income plays an intermediary role in the social capital’s promotion of class identification, among which income exerts the greatest intermediary effect in the social network and the class identification,at15.47%.