Celaomiao Depression，Urad Rear Banner ( Wulate Houqi )，located to the north of Mount Langshan，in the west of Inner Mongolia，is filled with Cretaceous clastic rocks，covering 850 km2. According to the former studies on the sedimentary facies and paleogeography in the Celaomiao Depression，it was believed that the clastic rocks of the Early Cretaceous Bayingebi Formation were mainly supplied by the neighboring orogenic belt, Mount Langshan, to its southeastern margin. It means that Mount Langshan had already been uplifted in the Early Cretaceous. However，there is no evidence to support this model. This paper’s research indicates that the source area of the Early Cretaceous clastics in the Celaomiao Depression was a fossil orogenic belt situated to the north and Mount Langshan had not been uplifted yet.Methods: The authors of this paper conducted field expeditions in the Celaomiao Depression and the Mount Langshan. Using the foreset beddings/laminations and ripple marks as the major indicators of the waterflow direction, the authors of this paper measured the attitudes of the sedimentary beds and the sedimentary structures on the outcrops of the Early Cretaceous Bayingebi Formation, recovering the original paleocurrent directions of the depression during the Early Cretaceous through stereographic projection. In this paper, the authors provided the data of field attitude measurements, stereographic projection results and rose diagrams of paleocurrent directions in the Celaomiao Depression, analyzing its paleocurrent regime and the provenance direction.Results: The authors of this paper got 46 sets of foreset beddings/laminations and 5 sets of waveinduced asymmetric ripple marks measured on the outcrops of the Early Cretaceous clastic rocks over the Celaomiao Depression (Table 1). All the measurements indicate that the paleoflow directions were mainly from north to the southeast with a range of 140°~210°, perpendicularly pointing to the extension trending of Mount Langshan (Figure 4 and 5).Conclusions: This paper’s investigation shows that the Early Cretaceous paleocurrent directions were mainly from north to the southeast in the Celaomiao Depression. This means that the provenance of the Early Cretaceous Bayingebi Formation was a fossil orogenic belt situated to the north of the Depression. Obviously, Mount Langshan had not been uplifted by the end of the Early Cretaceous and could not have been the source area of the Celaomiao Depression.