Social trust includes the socially acquired and certified expectations and obligations of
people to each other and to institutions and organizations in their community. In this paper, we examine
the relationship between types of trust including fundamental trust, interpersonal trust, the generalized
trust and institutional trust with attitudes toward new population policy. We have also tried to answer the
question what is the relationship between types of trust with attitude toward new population policy. The
research method is survey type that there were selected and studied 380 citizens of Yazd using
multistage cluster sampling method. A standard questionnaire was used to collect data. The inferential
statistics including Pearson correlation coefficient, t-test for independent groups and regression analysis
were used to analyze the data. The descriptive findings suggest that social trust to the new population
policies in Yazd is on medium and high levels. In explanatory level, there is a significant relationship
between basic trust, interpersonal trust, generalized trust and institutional trust with attitudes toward the
new population policies. According results of t-test in two independent samples, there is a significant
difference between attitudes toward the new population policies in both men and women. The results of
stepwise regression analysis showed that four variables (basic trust, interpersonal trust, generalized trust
and institutional trust) explain 33.2% of changes in criterion variable (attitude towards the new population
policies) totally.