Abstract: Researching the relativity between the lunar surface's dimension and roughness may contribute significantly to the stratigraphic study of the moon.The laser detector's data from Chang'E1 satellite.The selected Mare Humorum region of the lunar,and the SPSS statistical software were used to determind the best fitting model about the lunar surface's dimension and roughness parameters.The results show that the fractal dimension can be characterized as an independent parameter to represent the degree of rough surface.For the Mare Humorum region,it exists increasing relationship between the fractal dimension and surface roughness,and the Mare Humorum's hypsography has great disparity.Through the relationship between the fractal dimension and roughness,we can calculate any contour's roughness when we know the fractal dimension of the contour,vice versa.For the other regions of the moon,this method also can be used to study the relativity between the lunar surface's dimension and roughness so as to study the lunar's evolution process.