Abstract: Youshashan oilfield belongs to complex fault block oil reservoirs with thin inter-bedded layers and long intervals,being of the characteristics of multiple oil layers,large longitudinal span,thin sand-shale inter-bedded layers,strong heterogeneity,etc.Aiming at the problems of Youshashan oilfield development at present such as quick water cut rising,low degree of reserves producing,imperfect injectionproduction system,and poor water injection effect,on the material basis of oilfield verified geological reserves,according to feasibility study of layer series subdivision,the subdivision development plan by block and layer series has been established.And therefore,obvious development adjustment results have been achieved after implementation.