As the performance of foam flooding is dominated by foam stability which may be reduced in the presence of oil，development of foam system with improved foam stability has become increasingly important in the area of enhancing oil recovery of the foam flooding. The relationship between oil and foam stability was investigated by foam decay measurements and microfluidic control method. The effect of interfacial tension（IFT）between oil and foam system on the foam stability was examined through certain oil and different foam systems. Reaction between emulsified oil drop and bubbles was evaluated. Experimental results show that the half-life decreased considerably for the low-IFT foam systems，and oil has greater influence on the lower-IFT foam systems. Additionally，oil with lower surface tension would affect foam ability more significantly. Because larger relative molecular weight of oil and surface tension will bring difficulties in spreading on the gas-water interface with weaker reaction of the foam.