The farmers’ income gap between regions in China is the problem of agricultural sector, and it also relates to the rural-urban income gap problem. It means, we have to push up farmers’ income in order to narrow the gap between urban and rural areas. Farmers have to increase both of agricultural income and off-farm income in order to increase their whole income. Especially, it’s very important to increase off-farm income, because it has the biggest proportion in their income. Almost developed countries have same trend in the change of farmers’ income structure. So, in this paper, we focus on the changing trend of farmers’ income structure, the off-farm income gap and the wageincome gap between regions and the reasons for bringing that kind of gaps. China also has the same type of trend that the proportion of wage-income in farmers’ income is gradually increasing with other countries. Therefore, relative and absolute contributions of wageincome to the increase in farmers’ income are more than those of agricultural income, property income, transfer income, etc. But there is significant difference in farmers’ income level and structure between provinces(including autonomous regions and municipalities) and between regions(eastern, central, western). At the same time, in this paper, we use “Theil index” to analyze the farmers’ income gap between regions. The results show that the income gap between regions has more influence on inequality of farmers’ net income than the income gap within a region. On the contrary, the income gap within a region has more affect on inequality of farmers’ wage-income than the income gap between regions. In every region(eastern, central, western), trends in inequality of farmers’ net income and wage-income are very similar. The proportion of wage-income in farmers’ income is getting bigger. So, inequality of wage-income could make inequality of farmers’ income within a region or between regions get worse. Actually, Theil index analysis show that the farmers’ wage-income gap in eastern region and central region is narrowing, but in western region which its economy is relatively underdeveloped and employment opportunities in the non-agricultural sector are not enough, the gap is widening. Therefore, it’s very necessary to standardize labor market and promote more balanced regional development in order to increase farmers’ income.