Abstract: Diversified planting emerges as a pivotal strategy in ensuring effective food provision and addressing the challenges of climate change. Based on data from 1 201 farmers in China’s major grain-producing regions of China, this study empirically explored the impacts of diversified planting implementation on farmer′s   net plantation income, by employing the endogenous switching regression and quantile regression models. The results showed that: (1) Farmers that adopted diversified planting experienced a significant increase in net plantation income, compared to the non-adopters. (2) Variations existed in the income effects of diversified planting implementation among the farmers with different degrees of net plantation income. Specifically, the farmers with a lower net plantation income witnessed a substantial increase in net plantation income following the diversified planting, while the ones with higher net plantation income counterparts did not have significantly benefits. (3) The extent to which diversified planting might enhance farmer′s   net plantation income varied depending on the degree of diversification. The efficacy of diversified planting in enhancing farmer′s  net plantation income initially strengthened and subsequently diminished as the degree of diversification increased. When the diversification index (SID) was in the range of (0.4,0.5\], the enhancing effect was notably strong. Based on the above conclusions, it was imperative for relevant governments to develop tailored promotional strategies that matched the farmers with varying levels of net plantation income. There should be a particular emphasis on guiding and encouraging farmers with lower levels of net plantation income to engage in diversified planting. Furthermore, it was essential for the government to assist farmers in selecting the appropriate degree of diversification to enhance their net plantation income.