Abstract: The Stackelberg competition game and interconnection quality sequential equilibrium between two IBPs(IBPs: internet backbone providers) is studied to promote internet development and lay out reasonable interconnection policy.For the former,it emphasizes on the relationship between the corporation profit,social welfare and interconnection quality.It concludes that Interconnection between IBPs must be hierarchical and differential and interconnection quality to a certain extent is essential.For the latter,if Interconnection quality between the mature services or the old consumers is high,the IBPs must implement high interconnection quality between the new services or consumers.It also concludes that when the scale of internet is low,interconnection quality between IBPs must be high.