Abstract: There were many fluid flowing types which could be defined as single linear flow,radial flow,Bilinear flow transitional flow and biradial flow in the tight oil reservoir.One methodology was introduced in the paper to analyze the flowing types of the muti- fracturing horizontal well in tight oil by well performance.More than 600 muti- fracturing horizontal wells' performance were analyzed in Bakken oilfield of North America.And most of the wells show the linear flow from the fracture system to the wellbore.The dual porosity characteristics was shown in a lot of wells.