Social trust is the main component of social capital. In this regard, subjective welfare is one of the important aspects of human life. Based on the human needs growth, it must be considered both objective and subjective aspect of welfare. The present study tries to use survey method and collect data by cluster sampling among 381 persons of 20-29 Youth in Tehran as the sample of this research. The results show that there is a positive and meaningful relationship between social trust and subjective welfare. But there is a negative relationship between deprivation and confidence. Hence, changing in the variable of social confidence will cause change in the subjective welfare and its indexes.