Abstract:  According to the basic principles of replacing oil by water flooding, we have summarized 3 factors which affect flooding effect based on geological models, including the turnover rate of oil and water near to wellbore, the oil and gas enrichment level of immediate vicinity of wellbore and the oil and gas replenishment rate of distant place of wellbore. The wells failed in water flooding have been classified and the corresponding countermeasures have been put forward.