Abstract: Effects of water and fertilizer coupling on photosynthetic characteristics and yield of pumpkin were investigated at conditions with different water and fertilizer treatments. The results showed that: the influence of water and fertilizer factors on the pumpkin photosynthetic characters and yield are great, water and fertilizer coupling was not significant under the water stress situation, water and fertilizer coupling was restricted eath other under the low water situation, water and fertilizer coupling was increased eath other under the high water situation. The ingle factor effect is: N>water>P, the coupling effect is: nitrogen and water coupling>nitrogen and phosphorus coupling>phophorus and water coupling. The appropriate fertilization level (nitrogen 50kg.hm-2, phosphorus 35 kg.hm-2) can increase the photosynthetic rate and yield of pumpkin when the water level was appropriated.