Abstract: Considering the high cost of gas injection in conventional foam flooding,low gas liquid ratio foam oil flooding system composed with gemini surfactors 9BS-5-0,bataine and NaOH.Lab experiment measure the resistance factor,resistance coefficient to evaluate foam plugging ability.The resistance coefficient produced by foam is equal to the polyacrylamide with 0.15% mass faction.Effect evaluation of Low gas liquid ratio foam flooding under different gas liquid ration(0.05∶1~2∶1) indicate that recovery efficient increase is obviously better than pure surfactant system when mixed a few gas in the surfactant.When gas liquid ratio is 0.15~0.20,oil flooding system oil increase effect per unit is the best,when gas liquid ratio is 0.20,it shows: with the oil flooding system amount increasing,oil flooding agent per unit oil increment decrease,but recovery efficiency added value and comprehensive index increase.