The purpose of this paper is to identify and specify the consumer characteristics and the factors affecting their green purchase behaviour. In other words, this research tries to answer to these questions: What factors affect green purchase behavior of population, and what factors have more effects. The data are collected through a survey of students in Islamic Azad University - Qazvin Branch in 2011.418 students are considered as final sample. A questionnaire divided to 5 parts measures 18 independent variables in term of demographic, ecological knowledge, attitude and value aspects and one dependent variable.The results indicate that, by four aspects mentioned above, only the value affects the green purchase behavior of the population. Among 18 variables, four variable including religious commitments, collectivism, importance and inconvenience of ecological behaviours have effects on the green purchase behavior of population. Unfortunately, green marketing and its relevant topics are not so prevalent between consumers even the students as educated people. As usual and like other products, green product is not so tangible and well-known.This makes the process of research more difficult. Findings help the companies and organizations to develop and promote friendly behaviours toward environment.The conceptual framework of this research is new and consisted of various researches.Furthermore, the impact of religious commitments on green purchase intention and behavior has not been yet examined. However, its effect on green purchase intention will be observed at the present study.