Not all learnings come from direct observation or personal experience, sometimes people have to learn knowledge from second-handed materials. Given information could be from multiple informants, how to distinguish and select reliable informant becomes very important. Early childhood is one of the best period for learning and selective trust appears to be a hot spot in the developmental psychology field. Studies in this filed would help researchers to understand the developmental trends of cognition and knowledge learning in early childhood. It would benefit the early education as well. Previous research indicated that preschoolers would select the informant to trust by epistemic information and social information. However, the relations between selective trust, theory of mind, and executive function remained unclear to date. Some researchers argued that selective trust was associated with theory of mind because both of them appear at age four. Other researchers thought that preschooler’s selective trust was based on executive function. The previous inconsistent results might due to the limited measurement of theory of mind and executive function, or uncontrolled language ability. In addition, lack of longitudinal data might confuse the predictive direction of these variables.