Abstract: In order to study the role of agricultural mechanization in plant product industry,based on the analysis of the characteristics of agricultural mechanization in the Northeast of China, profit portion of agricultural mechanization in plant product industry of the Northeast was estimated by the method of “with and without product comparison method”, the main influence factors of the profit portion were analyzed and development suggestions on agricultural mechanization in the Northeast of China were put forward. Study results showed: (1)The profit portion of agricultural mechanization in net income of plant products industry in Northeast of China in 1998 was 28.74%; (2)Under decline of plant product price and agriculture economic benefit, the agricultural mechanization will be more and more important.