Abstract: The main purpose of this article was determined to various amount of fertilizer and planting densities to adapt the high-yield cultivation model of‘Jincao 4’. Using the method of group physiology,and adopt two factors randomized block design by using the group, to study the affects agronomic traits and photosynthetic indexs in‘Jincao 4’after carrying out different densities and amount of fertilizer. The results showed that the plant height, stem diameter, tiller number, the biological yield, the yield of dry weight, and photosynthetic indexs of‘Jincao 4’have varied significantly under the treatments of different densities and fertilizer in middle region of Shanxi . The plant height , stem diameter, the biological yield , the yield of dry weight ,LAI and net photosynthetic rate were the highest under F2D3;However, the tiller number, chlorophyll content, stomatal conductance were the highest under F2D4、F2D2 and F3D1; F2D3 to take the second place. It was suggested that the planting density of 390000 plants per hectare and fertilization 750kg perhectare was appropriated for‘Jincao 4’.