At present, our country fit IV emission norms for heavy diesel vehicles more choice of SCR exhaust manipulation skills. SCR converter in some of the most important car urea solution that is, before it did not enter the SCR converter has been transformed into a fiery exhaust ammonia, while the chemical NOx and ammonia within the catalytic converter occurred The reaction, is converted to nitrogen and water, decreased emission of nitrogen oxide compounds and particulates. Car urea solution is clear, colorless, odorless, non-toxic liquid brightly lit for selective catalytic NOx reductant. Can be useful to decrease emissions of NOx and particulates sedan tail, down fuel consumption. State IV emission norms for the satisfaction of needs, selection of SCR exhaust vehicle handling skills necessary to increase the urea solution as a catalytic reducing agent, to ensure that vehicle emissions compliance. Trooper high quality environmentally friendly vehicles with urea (green car with urea water) and heavy goods vehicles and buses are the main factors causing global warming and air pollution. To address these two questions, Taiwan and the European Union has begun to implement five / six environmental regulations (EURO 5/6), which for car manufacturers is a great challenge. European heavy commercial vehicle sector contains DAF, Mercedes Benz, IVECO, Renault, Volvo, etc. To ensure that new EU environmental regulations fit five EURO 5 and EURO 6 emission norms six, are selectively chosen SCR catalytic converter (Selective catalyst reduction), this system has a decreased nitrogen oxide and particulate emissions, fuel consumption, and a decline of the two kinds of important features. SCR converter is the most important and some that is AdBlue? / DEF catalyst reductant (AdBlue), which is approximately 32.5% of the use of urea and water formed, when it has not entered into before the catalytic converter is hot exhaust converted into ammonia, and ammonia and nitrogen oxide catalytic converter within the chemical reaction, is converted into nitrogen and water, decrease emissions of nitrogen oxides and particulates, together also get some suppression of global warming effect.