In order to have a more objective position on the world level of the standard value of vehicle load in China and make a foundation for the revision of the resent standard of Highway Bridge. This paper has explained the China's new and old code and the United States HL-93 specification for the design of vehicle loads, then take 6, 8, 10, 13,16, 20,30 meters long span bridge with T shaped beam for example, to make a systematic calculates of mid-span moment and shear force at supporting point of T-shaped beam, which is under the action of vehicle load in the Chinese and American Codes. In the end, the absolute value and the relative value of the load effect are analyzed systematically. The results show that: compared with the United States, the Chinese standard is relatively conservative and not intuitive, China's current vehicle load standard specification in the international is roughly in the middle position, considering the contact with the original specification, the appropriate reference to the United States.