Root system plays an important role in the formation and permeability of soil macropores. Aiming to clarify the numerical relationship between root biomass distribution and soil macropores characteristics, a naturally grown Chinese fir in JinYun mountain was selected as research object. The macropore area and root distribution characteristics on 4 dye tracing treated soil profiles in field were observed, and then a series of water penetration tests were conducted using self-designed constant head device for soil sampling in dyed and undyed zone in Lab. Results showed that:(1) The dyed area of soil was different for different soil profiles and different soil depths. The farther away from the trunk of the tree, the larger the dyed area, while the closer to the trunk, the smaller the dyed area, and the overall depth increased. The dyed area ratio of each section above all decreased. (2) The four soil profiles mainly showed a trend of decreasing root coefficient with the increasing soil depths. The root diameter mainly concentrated between 0.2~10 and 0.2~1 mm diameter. (3) The dyed area had a greater stable outflow rate than the undyed area. The outflow rate of the dyed area in the four sections was 1.97, 1.81, 1.77 and 1.70 times those of the undyed area, respectively. As the depth of the soil layer increased, the number of macropores decreased, and the radius of the macropores ranged from 0.3 to 1.7 mm; (4) The macroporosity and root biomass were positively correlated with the permeability coefficient, and the macroporosity contributed 94.5% of variation in the permeability coefficients, while root biomass contributed 87.4%.