Objective: To improve cotton planting technology according to cotton canopy characteristics. Method: Adopt the way, in film with drip irrigation relatively high and low two irrigation quantities, design such 5 different nitrogen strategy plan, completely combination of 10 treatments, determine and analyze the 10 with cotton canopy characteristic and yield growth the variation characteristics. Result: Whether irrigation level is high or low, LAI value and K value each of them with "behind the front less" application of N fertilizer was significantly higher in the bud stage; In the bloom stage under the high irrigation, LAI value was significantly higher with "behind the front less" application of N fertilizer; in the Bud stage, bloom stage, boll stage under high irrigation, with "behind the front less "application of N fertilizer, LAI value was relatively fast increased, but the TC value and T value were decreased relatively quickly; in the bud stage, bloom stage, boll stage under low irrigation, MFIA value was decreased relatively quickly with "front behind much less" application of N fertilizer, but the K value was increased relatively quickly; when the irrigation is higher, the fine under the control of water and nitrogen yield with LAI value was positively related to change, LAI value and seed cotton yield each of them with "behind the front less application of N fertilizer was significantly higher. Conclusion: When the Irrigation is relatively high, the LAI of cotton in bud stage and bloom stage showed the highest value when using two top-dressing with the behind the front less" strategy of nitrogen, to the effect of LAI value, TC value, T value, K value, and yield in growth stage was stronger than that "front behind much less" strategy of nitrogen.
