The emissions from 7 urban freights were tested using portable emission measurement system, and analyzed based on VSP method. The results show that both gaseous pollutants and PM emissions increase with the rising VSP. With regard to emissions of CO and HC, they decrease with the elevated speed and acceleration. PM and NOx emitted from China IV vehicles are significantly less than those from China III vehicles, while emissions of CO and HC exhibit different tendency and further work should be performed. In addition, speed and acceleration show slight influence on NOx emissions. The VSP plays an important role in the emissions from urban freight trucks. Therefore, a comprehensive evaluation of the emission characteristics of the urban freight trucks in megacities is needed for taking effective measures.