Abstract: The wood with the moisture content of 9%,10%,11%,12%,13%,14% and 15% were used to measure the tangential direction toughness, and wood with 12% moisture content was also used to measure the radial direction toughness. After the survey, the revision model of toughness with moisture content were established. The toughness of radial and tangential direction of Cunninghamia lanceolata were 46.112 kJ/m2 and 37.514 kJ/m2 respectively. The toughness of radial and tangential direction of Castanea seguinii were 82.994 kJ/m2 and 76.271 kJ/m2 respectively. The differences of toughness value between the radial and tangential direction were remarkable at 0.05 level for both C.seguinii and C.lanceolata. So the “Method of testing in toughness of wood” should include the revision model of toughness with moisture content A12=AW[1+0.02(W-12)] and the method how to measure the radial toughness of wood.