Abstarct: In this theoretical work we are intended to study the temperature dependent of thermal conductivity in GaN and ZnO semiconductors. These materials with wide direct bandgaps have attracted a large amount of attention for their application in high-power and high-temperature electronics and optoelectronics devices. Various factors may affect on thermal conductivity of a material, partly related to intrinsic properties and partly due to extrinsic ones (such as dislocations and impurities). Knowing each of these factors and their affectness on thermal conductivity of a material may help to build high efficient thermoelectric devices, which directly convert thermal energy into electrical energy. Here in this research we have studied the effect of phonon scatterings in GaN semiconductor in various conditions including: bulk mono crystalline samples, amorphous-crystalline ceramic and nano wires; and in ZnO semiconductor in various conditions including: pure ceramic, with different doping (Ni and Al), and finally ceramic with dually impurities of Al and Ga. In analyzing the experimental data we have used the thermal conductivity theories in the solids also we have used fitting process through least square fit procedure for the experimental data and theoretical values. The experimental reported data in GaN semiconductors show, nanowire samples have a lower thermal conductivity compared with that of the bulk laxyers. Our analysis indicates that this variation could be related to the increment in the extended and also point defect densities in the former samples than the latter ones. In ceramic ZnO semiconductor samples we found the presence of intentional impurities have an important role in reduction of thermal conductivity of the material that enhances as the the impurity concentration increases, especially in the dually doped samples.