The Northwest China in this paper refers to the broad region bounded by the Helan Mountains and Liupan Mountains to the east, and by the Kunlun Mountains to the south. Based on the study of stratigraphy and petrology of outcrop and well sections, according to the single factor analysis and comprehensive mapping method, the various single factor maps of the Lower, Middle and Upper Cambrian and lithofacies palaeogeography maps of the Early, Middle and Late Cambrian in Northwest China were compiled. These lithofacies palaeogeography maps possess three characteristics, i.e. quantification, multirank and multitype. Quantification means that the determination of each palaeogeographic unit is based on quantitative single factor data and maps. This makes palaeogeography developed into the quantitative stage. Multirank means that palaeogeographic units are classified into three or more than three ranks. For instance, lands and seas are the first rank. In the seas, the platforms, basins and slopes are defined as the second rank. In platforms, the banks, tidal flats, and lakes are further drawn out as the third rank. Multitype means that palaeogeographic units, especially the second and third rank units, can be further divided into different types on the basis of their rock types. For instance, platforms can be divided into carbonate platforms, clastic platforms, etc.；basins can be divided into siliceous basins, clastic basins, limestone basins, flysch basins, etc.；and banks can be divided into sparry grain banks (penebanks, embryonic banks),etc, limemud grain banks (penebanks, embryonic banks), mixed banks (penebanks, embryonic banks) . The framework of lithofacies palaeogeography of the Cambrian in Northwest China can be summerized as following. There were both lands and seas. In seas there were platforms and basins distributed alternatively. In platforms there were scattered banks, flats and lakes. Between platforms and basins there were slopes. The features of lithofacies palaeogeography of the Xinjiang and Beishan Area and that of the West Kunlun, Gansu and Qinghai Area are different；however the framework and evolution stage of lithofacies palaeogeography and the transgression process of the whole Northwest China are just the same.
