Abstract: In the passage of time and the development of economic theories new variables as factors affecting each are introduced. So, the relationship between economic growth, financial development, trade openness and environmental quality has always been a major concern of researchers, each of which examines the relationship between some of these variables. However, comprehensive model that considers potential interaction between different sets of variables is ignored. In this study, in order to cover a comprehensive model and fill gaps in the existing literature, subsets for OPEC member countries are examined. For this purpose, the estimation method of simultaneous equations and GMM using panel data over the years 1990-2010 is used. The results indicate a reciprocal relationship between carbon dioxide emissions and economic growth. Also, economic growth and the degree of trade liberalization also have a bilateral relationship and mutually affect each other. But the relationship between economic growth and financial development is a one-way relationship. This means that financial development affects economic growth but economic growth has no significant effect on financial development. The relationship between carbon dioxide emissions and financial development is also a two-way relationship. Also, the results of the model suggest no relationship between carbon dioxide emissions and the degree of trade liberalization. The results show that the relationship between financial development and trade liberalization is a two-way relationship. In addition Sargan test shows the correct specification of the econometric model.