Abstract: 396 samples of tobacco leaves at C3F grade from 87 Yunyan varieties in China main production area of flue-cured tobacco were detected.The relationship between the starch content and the physical properties was analyzed by using multivariate statistical methods Multiple Regression equations were constructed.The relationship between tobacco starch content and leaf density matched the growth model ?=e(0.5247+0.0124x)description.The relationship between starch content and equilibrium moisture content matched the power model ?=1873.9717e-2.193x description.The relationship between starch content and leaf thickness matched the quadrati function model ?=15.1955-260.4228x+1494.0512x2 description.The relationship between starch content and pulling force matched the logarithm model ?=6.1118-2.6737 lnx description.The relationship between starch content and leaf filling value matched the inverse matrix model ?=-1.3542+25.5112/x description.The relationship between starch content and single leaf weight matched the exponential curve model ?=1.851x0.0916 description.The relationship between starch content and stem ratio matched the compound model ?=14.84670.9614x description.The relationship between starch content and cut tobacco yield relationships matched the S model ?=e(4.8626-306.049/x) description.All the curve regression equations were extremely significant.Flue-cured tobacco starch content was significantly positive related with weight, density, thickness, cut tobacco yield of one single leaf, and significantly negative related with filling capacity, equilibrium moisture content tobacco pulling force and stem ratio.Path analysis between starch content and physical properties in flue-cured tobacco leaves indicates that:The physical index of the weight, density, pulling force and equilibrium moisture content of a single leaf has direct and significant effect on the starch content of tobacco.