The lake-level rise and fall cycles is the main factor controlling the distribution of reservoir rocks . Therefore , synchronous reservoir beds can be distinguished and correlated on the basis of the actual depositional cycle boundaries. The western Liaohe depression belongs to a faulted lake basin. The cyclical depositional seqence framework of the basin, which is different from that of the passive continental-margin basin, can be described with the cycles of lacustrine transgression and regression (T -R). T -R cycles of different scales or different freqences correspond to oil zones, oil series and sandstone series. An oil zone is roughly equivalent to a third-scale global cycle which results from the episodic tectonic activity. The oil series and sandstone seriers are respectively equivalent to the fourth- and fifth-scale global cycles which are ascribed to the Mi-lankovitch cycle. The reservoir sandbodies including oil series and sandstone series distinguished by the T - R cycles have good regularities of lateral and vertical distribution. The regularities are of benefit to reservoir development.