Variation of cultivated land quality in 10 major cities and its driving forces are introduced in recent 10 years. And economic development and population growth are the common driving forces for the reduction of cultivated land in coastal cities. Among them, economic development is the main driving force. Taking Huludao City as an example, driving factors of cultivated land variation in Huludao City are studied by Principal Component Analysis according to the relevant statistical data in the year 1998-2007. Result shows that in recent 10 years, total cultivated land area has increased in Huludao City, especially in the years 1998-2002. Driving force of cultivated land variation in Huludao City can be summarized as economic growth, population growth and agricultural science and technology development. Based on this, relevant measures toproject cultivated land are put forward: controlling population, reducing land pressure; strengthening the protection of cultivated land and basic farmland, stabilizing cultivated land quality and quantity, strictly controlling the nonagricultural scale of cultivated land, improving the level of land economical and intensive use. Enhancing land consolidation, reclamation and development, increasing agricultural science and technology input, and guiding the adjustment of agricultural structure.