Abstarct: This study was designed to evaluate the effect of private ownership on export intensity in the industries manufacturing vehicles and transportation of Iran. Moreover, the effect of competitiveness, firm size and R & D costs variables on exports in these industries were examined. To estimate the GMM method were used in this study, Data using International Standard of Industrial Classification (ISIC) at the 4-digit codes related industries manufacturing vehicles and transportation of Iran for the period (1994-2012) have been obtained. The results show that private property, costs of research and development and competitiveness in the export intensity of manufacturing industries vehicles and transport are positive and meaningful effect. It was also noted firm size has no significant effect on export intensity. According to the results obtained, obstacles and support the export-oriented firms in the industry privately operated, can be the industry's policy priorities, As well as providing on entry for private firms in these industries are planning to production and exports could be a step to improve production and foreign trade. Experimental results obtained from this study were obtained using dynamic panel. In panel data, time series data and cross-sectional data are combined, thus The properties of heterogeneous sections disappears, not only can provide information useful for estimating econometric models but baxsed on the results obtained can take considerable policy. In this way data from the Statistical Center of Iran for firms with 10 employees and more in the manufacturing industries vehicles and transportation , over the years 84-1392 have used . Export intensity as the dependent variable and private property are presented as an explanatory variable. Moreover, the effect competitiveness, firm size and R & D costs on exports in these industries were examined also The first difference dependent variable is used as an instrumental variable. The main objective of this study was to explore the effects of private property in the heavily export manufacturing industries and transport vehicles Iran. Due to the gap in studies related to the effect of ownership and exports in industries of Iran, the necessity of this research will be revealed. According to the results, the main hypothesis of research baxsed on private ownership has a positive effect on export intensity in manufacturing industries and transport vehicles Iran is confirmed. The second hypothesis as that, no matter how competitiveness in the sub-industries and transportation vehicles increases, exports of this sector increases, was confirmed. The third hypothesis suggests that the larger the size of the firm export vehicles and transport industries will also increase, this hypothesis was rejected. Finally, the fourth hypothesis that by increasing spending on research and development in vehicles and transport industries will increase the country's exports in this industry sector, was accepted.