Abstract: The maceral classification of Palaeozoic source rock in Tarim basin has been proposed based on the detailed microscopic examination. The hydrocarbon: generating potential of Palaeozoic source rock has been preliminarily evaluated by combining the petrology of each maceral with organic petrology. Cambrian source rock is dominated by secondary compositions, with low hydrocarbon-generating potential; Ordovician carbonate source rock is rich in alginate, with stronger hydrocarbon- generating capacity; the overmature Ordovician argillaceous source rock has low hydrocarbon-generating potential; Carboniferous argillaceous source rock is gas-prone while carbonate source rock is prone to generate both oil and gas.

Key words: Tarim basin, Palaeozoic, Source rock, Petrology, Characteristics, Source rock evaluation