Abstract: A between-subjects experiment of 2(victims on the scheduled route : relatives, strangers)×2(victim on the unscheduled route: relative, stranger)×4(Grades: 5, 8, 11, sophomore)with 480 students was conducted with trolley dilemma to investigate the effect of personal relationships on the ways of moral thinking of adolescence in different ages. The results show that: 1)A significant interaction effect between the two types of personal relationships of victims exists. When the victims on the scheduled route were strangers, participants made their moral decisions with rules-based thinking under the condition that the victim on the unscheduled route was their relative, but with outcome-based thinking as the victim became a stranger. Similarly, when the victim on the unscheduled route was their relative, participants made their moral decisions with outcome-based thinking under the condition that the victims on the scheduled route were their relatives, but with rules-based thinking as the victims become strangers. 2)There is a significant interaction effect between Grades and personal relationships of the victims on the scheduled route. Our study suggests that personal relationships in moral situation influence individuals′ moral thinking, and have an increasing effect on the ways of adolescences′ moral thinking, the transition period of the two types of moral thinking appears between Grade 8 and Grade 11. Our study supports the relationship regulations theory.