Abstract: From the braided river outcrops of Houcheng formation of Middle Jurassic at Junzhuang town, Mentougou region in Beijing, it is observed the cross?section of the braided river distributary channel is characterized by gradual thinning of thickness from channel center to channel wings. Considering the channel changing system, this paper presents the geometric model of the cross?section is that besides the thinning feature, it appears the unsymmetric semi?ellipse with flat top and swell bottom. Using the geometric model and the conventional “sand to sand and shale to shale”sub?layer correlation methods, the correlation of single sand body sublayer of the Enping formation in oilfield?A braided river sedimentary system in Pearl River Mouth basin is conducted. The result shows that the geometric model?based sublayer correlation method can be applied to explain the lateral difference between sand body number and sand thickness of interwells and longitudinal evolution pattern of the sedimentary center through the spatial distribution characteristics of braided river channels, and is more applicable in study of complicated sedimentary system like braided river, compared with conventional sub?layer correlation method