Abstract: Under the Controlled-release fertilizer (LCU) paddy research of Unbongbyeo, a Japonica variety, in the red soil hilly fields of southern Hunan for two consecutive years, with a systemic field observation combined with real time analysis.The result is: the tiller rice seedlings, Controlled-release Fertilizer LCU70≥NPK＞LCU50＞PK; while the rice panicle rates of controlled-release fertilizer LCU70 and LCU50 are 6.3% and 4.5% higher than those of urea treatment respectively.The increases of dry matters in leaves, stem and root are higher under the application of controlled release fertilizer than other treatments. Ranking by treatment, it will be: LCU70＞NPK＞LCU50＞PK. The controlled release fertilizer LCU70 also has the highest Leaf area index (LAI) 6.50, which 1.04 and 1.51 higher than NPK and LCU50 respectively.The yield of Unbongbyeo is: While the amount of nitrogen used in Controlled-release fertilizer is 70% of its in conventional fertilization (NPK), the rice yield is 6.72% higher than that of conventional fertilization, the yield difference is significant; While the amount of nitrogen used in Controlled-release fertilizer is 50% of its in conventional fertilization (NPK), the yields equivalent, the yield difference is not significant. It shows that the application of controlled release fertilizer can reduce the usage amount of nitrogen by 30%~50%.