Under the rapid social-economic development process, the income structure and arable land size among rural households are facing with increasing differentiation in China. How the regional-scale arable land use intensity and environmental risk triggered by the rural households' differentiation would be is a question that has not been widely discussed. To fill this research gap, this study established three step-by-step indexes, rural households' ER index, arable land use intensity (LUI), and environmental risk index (RI), to measure rural households' differentiation, regional arable land use intensity, and environmental risk, respectively. By gathering data from questionnaire investigation of 950 rural households in Shandong Province, China, the result showed a wide range of ER index (0.006-0.056), LUI (2748.90-6361.54), and RI (0.0966-0.5032). ER index based on farm income, nonfarm income, and arable land size among rural households showed different distributions among cities. Though huge differences of arable land use existed in different rural households, including land area, crop species, use of production materials (agro-machinery, fertilizer, pesticide), and attitude towards land transferring, the farmers' sense of belonging to farmland and their dependence on agriculture did not disappear in the process of rural households' differentiation. Moreover, as aggregated effects of rural households' behavior, differentiation of regional arable land use intensity and environmental risk appeared later and lower than the level of rural households' differentiation in the same city. Among this process, Laiwu, Weihai, and Yantai became "hotspots" with higher level of rural households' differentiation, arable land use intensity, and agro-environmental risk, respectively. This study pointed out a possibility of policy designation that prior controlling environmental risk of arable land use could be realized by identifying the rural households' differentiation on arable land use.
Keywords: Arable land use intensity; Differentiation of rural households; Environmental risk.