The role of neutral agents on evolutionary tolerance between two differentiated groups is discussed based on the replicator game model proposed recently. We show that, very different from the pure opposing case studied previously, dynamics of social tolerance with neutral agents is more positive and exhibiting rich interesting effects. The full intolerance steady state (0, 0) is unstable when neutral agents are taken into consideration and there are two type of evolution trajectory according to the population of the neutral agents. Especially, phase trajectories reach to the stable full tolerance steady state (1, 1) at any starting point if the population of the neutral agents is large enough, and the tolerance between different social groups can be a natural consequence of economic integration in the present of neutral agents. We show that neutral agents may remove the contradiction between the traditional idea of economic integration and the evolutionary game point of view. (C) 2017 Published by Elsevier B.V.