An experimental technique and mathematical analysis was developed to test the hypothesis that moisture diffusion coefficients of wood are exponentially dependent on moisture content. The relationship between the diffusion coefficient, <i>D, and moisture content <i>M, of <i>D=D₀ e<sÊ3M>s was shown to hold for longitudinal diffusion in yellow-polar sapwood, were D₀ was 1.71 x 10_-4cm₂/sec. and Ê3 was -0.133. Mathematical equations were derived to predict integral diffusion coefficients and moisture content distributions in wood whose opposite faces are subject to different relative humidities. Data from several literature studies supported the analysis of this study. -- AATA