Abstract：The relative abundance of tricyclic terpanes has significant indicative value for revealing organic matter sources, depositional environments, and thermal evolution stages. While traditional coal-measure source rocks typically exhibit low tricyclic terpanes content, anomalously high abundances of tricyclic terpanes (relative to hopanes) have been detected in coal-measure source rocks from the Ordos and Tarim Basins. Therefore, an indepth investigation of their distribution patterns, compositional characteristics, and formation mechanisms is of substantial significance. This study employed conventional geochemical analysis methods and gas chromatography-mass spectrometry (GC-MS) to systematically analyze molecular geochemical characteristics of 30 coal-measure source rock samples from the study area. The research demonstrates that tricyclic terpanes in coal-measure source rocks present two distinct abundance patterns: low abundance tricyclic terpanes (ΣTT/C30H <2) and high abundance tricyclic terpanes (ΣTT/C30H>2). The low abundance tricyclic terpane samples exhibit a C19-21TT decreasing distribution pattern, formed in freshwater oxidizing environments, with hydrocarbongenerating parent material primarily derived from higher plants, and at low thermal maturity. The high abundance tricyclic terpane samples display distribution patterns with C23TT or C21TT as the dominant peak, formed in saline, sulfur-rich depositional environments, with hydrocarbon-generating parent material mainly sourced from bacteria and lower aquatic organisms, reaching mature to highly mature thermal evolution stages. Correlation analysis between maturity, depositional environment, and parent material input parameters with Σ TT/C30H values reveals that parameters characterizing depositional environment and hydrocarbon-generating parent material show more significant correlation with tricyclic terpane abundance. The results indicate that brackish, high-sulfur coal-forming environments and increased input of secondary products generated by microbial transformation of higher plants in hydrocarbon-generating parent material are the primary controlling factors for high abundance tricyclic terpanes in coal-measure source rock extracts, while thermal maturity serves as a secondary influencing factor. The molecular composition and formation mechanisms of high-abundance tricyclic terpanes in coal-measure source rocks offer critical molecular geochemical evidence for recognizing coal-forming environments, identifying hydrocarbon-generating organic matter, and assessing thermal maturity, thereby providing theoretical and practical guidance for coal-measure hydrocarbon exploration.