广东省重点科技攻关项目 (98110 5 6 0 0 )，国家自然科学基金项目 (392 70 14 2 )
The 18 cultivation systems in Sanshui City of Pearl River Delta was evaluated by the help of Analytic Hierarchy Process. The results showed that the four systems of rice-water chestnut, vegetable-radish-radish, wax gourd-bean-tomato and wax gourd-bean-vegetable were both good in ecological and economical benefit. The two systems of wax gourd-wax gourd-vegetable-vegetable-vegetable and wax gourd-vegetable-vegetable-vegetable were good in economical benefit, and bad in ecological benefit. The systems of rice-rice, rice-rice-potato and watermelon-rice were rather good in ecological benefit, but bad in economical benefit. There were some potentials to enhance their economical and ecological benefits in the systems of rice-peanut-sweet potato, wax gourd-wax gourd-vegetable and wax gourd-vegetable-vegetable. The composition of crops should be adjusted and the management should be improved.