This work is concerned with the study of the impact of heat (160,180,200 and 220°C), and the time of exposure on cedar and sycamore woods for different times (2, 4 and 6 hour). The change in the color of the wood was studied. The mechanical properties, rate of mass loss, and decrease of density of the heat treated woods were evaluated. The surface roughness and the fiber separation were also studied using scanning electron microscopy (SEM), and the results showed that both types of wood were affected by heat treatment (160 and 180°C), as the surface smoothness increased for both. As temperatures rose to (200 – 220°C), there was a high roughness in the outer surface of the wood with increased separation of fibers. The anatomical structure of the wood was examined via (SEM), where the cedar samples showed higher quality in heat resistance than sycamore. The heat treated wood was studied using FT-IR spectroscopy to study the changes in the wood spectra structure, as well as X-ray diffraction pattern (XRD) analysis was also used to study the extent of change in the crystallization of cellulose.