Abstract: In this paper, the theoretical expression of the specific heat of wood is set up from the microstructure of wood and by applying some basic principles of physicomechanics. when the theoretical values of specific heat of 27 different species of wood with different moisture contents and temperatures are compared with the experimental values in the same conditions, it has been discovered that the maximum error is less than 11%, and the average error is within 5%.

Key words: specific heat of wood, theoretical expression