Abstract: 【Objective】 In order to research effects of slow-release nitrogen supply on yield and dry matter of Summer maize at lime concretion black soil． 【Method】 using Beiqing 340， five levels of control （C₀）， slow-release urea 70 kg / hm² （C₇₀）， slow-release urea 140 kg / hm² （C₁₄₀）， slow-release urea 210 kg / hm² （C₂₁₀） and slow-release urea 280 kg / hm² （C₂₈₀） were set up. 【Result】 The results of correlation and regression showed that with the increase of slow-release nitrogen fertilizer， Dry matter and yield increased first and then decreased. The correlation otherness between organic dry matter and yield character， the para correlation weight of stem and leaf sheath at R₃ and R6，others positive correlation， linear relationship between organic dry matter and yield character. 【Conclusion】 Comprehensive consider yield increment and the cost slow-release 210 kg/hm²（C₂₁₀）can be recommend fertilization model of maize in the area of study.