The lithological distribution of the Langshan Formation is roughly discussed in the north depression belt of the Cuoqin basin and especially in the Taricuo depression of this belt. Sedimentary microfacies of this formation are analyzed in the Taricuo depression. This formation has the best source and reservoir conditions in the Taricuo depression or even in the north depression belt of the Cuoqin basin. Its three depositional centers were the Geji depression area, the Dongcuo depression area and the Selincuo depression area. The Taricuo depression is located in the Dongcuo depression area. The lithological distribution of the Langshan Formation is roughly discussed in the north depression belt of the Cuoqin basin and especially in the Taricuo depression of this belt. Sedimentary microfacies of this formation are analyzed in the Taricuo depression. This formation has the best source and reservoir conditions in the Taricuo depression or even in the north depression belt of the Cuoqin basin. Its three depositional centers were the Geji depression area, the Dongcuo depression area and the Selincuo depression area. The Taricuo depression is located in the Dongcuo depression area.