Tier 3 level of the emission factor is a very useful tool for policy making and the need for GHG emission calculation. The existing national GHG emission factor was developed only for passenger vehicles prior to 2009, it is necessary to develop new GHG emission factors. This study was carried out for development of Tier 3 level GHG emission factors that used for national GHG emission estimated and policies necessary. For the development of Tier 3 emission factors, In this study, statistical validation of the results and the selection of regression models have been done. To review the accuracy of test results, uncertainty review was carried out.