Abstract: The lithology of Carboniferous igneous rocks in Zhongguai swell of Junggar basin is complicated and characterized by rapid lateral variation, large vertical thickness and low radioactivity, so natural gamma logging can not be used to accurately identify the lithology.The main rock types are analyzed based on core observation and thin section examination. Analyses on rock genesis and components are performed with elementary capture spectroscopy logging (ECS) and the mass fraction crossplot of SiO2, Fe2O3 and TiO2 is established to classify chemical component of igneous rocks. According to texture and structure information reflected by FMI logging, an imaging mode chart is established to further identify the lithology. Based on the above, conventional logging response features are analyzed for igneous rocks with different lithologies, structures and mineral compositions. Then the ECS and FMI identification results are integrated with the conventional one, analyzing the conventional curve sensitivity and establishing neutron porosity?density crossplot, finally, the conventional logging curves can be used to classify the lithologies of igneous rocks