Social factors, such as public opinion, values, ethics, moral standards, could guide people’s behavior to some degree. In this paper, we introduce social orientation as a motivator factor into the Nowak model, and discuss the variation of cooperation proportion under the function of motivator factor and betrayal temptation. Results show that motivator factors can promote cooperation proportion, and there is a motivator factor threshold. And a jump point is present in the value, on each side of which cooperation proportion has a small change. Reduction of betrayal temptation can also promote cooperation proportion, and there is a betrayal temptation threshold. And the value is corresponding with a jump point. And cooperation proportion changes very little on each side of the value. In addition, when betrayal temptation and motivator factor both play a role in a system, there are always cooperators and defectors in coexistence.