This is n farther study to evaluate the feasibility of using the temperature difference between lumber-renter and kiln-air as a guide far estimating the final moisture canted of the wood during high-temperature kiln drying. Lemonscented gum (Eucalyptus citriodora) and Taiwan incense-cedar (Calocedrus formosana) lumber, 3 and 5cm (T)×12cm (W)×160cm (L), were used for this study. Each group of the test boards was dried at 100℃ with mixture of steam and air process. The results of this study indicate that: 1.The temperature difference between lumber-center and kiln-air can be used as a guide for estimating the final average moisture content of the wood during high-temperature kiln drying, but it is not suitable for some species which are susceptible to severe internal checks. 2.The final average moisture content is about 6%, when central-temperature of the samples up to 109℃ or 1℃ below the kiln air for 3 and 5cm Taiwan incensecedar to be dried at 110℃. 3.Lemon-scented gum 3 and 5cm lumber cannot be subjected to temperature about 110℃ without inflicting serious degrade from surface checks and end-grain honeycombing; in other words, high-temperature kiln drying is not a system to be used for Lemon-scented gum lumber.