Abstract: Twelve years old Castanea mollissima cv. ‘yanshanzaofeng', a main cultivating variety in Qianxi county of Hebei province, was chosen as test materials. Sample trees with natural open center shape and different main branch number as well as opening angle were selected in the study. The chestnut canopy light distribution character was analysed by measurements of canopy light intensity in different canopy layer and direction under different shoot number and opening angle, and the effect of tree structure on yield and quality was also investigated. The results showed that there was certain influence of different main branch and opening angle on light intensity, yield and quality. When main branch number remained the same,the light intensity increased gradually with the opening angle increasing. The crown volume with the relative light intensity less than 30% was the smallest when three main branches were kept and their opening angle were more than 60°.The proportion of the crown volume with the relative light intensity less than 30% total crown volume was 42.857%. When the opening angle kept unchanged,there was no significant change in yield and quality with the increasing of main branch number. The highest yield per unit area was 0.225 kg/m² when the opening angle of three main branches was over than 60°.Comprehensive analysis showed that three main branches with opening angle more than 60°was the best structure for chestnut with natural open center shape.