Abstract: The tobelite-bearing tonsteins are more widely distributed in the coal beds of Taiyuan and Shaxi Formation of,the Carboniferous Permian coal mersures in Northern China.can be divided into the six rock lypes.Their lithological features and occurrences characterisrices of the tobelites in the tonsteins are described in detail.The analytical results show that the tobelites are 1 M type.The tobelites are formed by alternating Kaolinite and llite in the tonsteins under the eflect of NH₄⁺ formed by the degradation of coalforming plants and other organic substances,under the condition of acid nedium,below 120℃.The tubelite can be regarded as a index mineral which forms and reserves the coal bed gas.