Split application N fertilizer and using Spad resulted showed spad valus increase by application N fertilizer at different growth stage. thus, used spad in rice feild and split application N fertilizer based spad values can reduct of used nitrogen fertilizer. It was also revealed that grain yield increased significantly with nitrogen fertilizer. The results revealed that N application method based on growth diagnosis helped in saving N applied fertilizer and increasing grain yield. Timing of nitrogen application can apply four or three times at different growth stage based crop need and spad threshold and crop-growing condition at each location.