The body lightweight is important to the vehicle design and development, which has become one of the main research subjects in vehicle industries and research institutes. One area of concern for product engineering, however, has been the higher density of steel versus alternate materials. The concept of combining various steel options into a welded blank was developed to enable product and manufacturing engineers to "tailor" the blank so that steel's best properties were located precisely within the part where they were needed. This process not only reduces the weight of the finished part, but also can be used for part integration, thereby eliminating many reinforcements and stiffeners.Engineered systems in today's automobiles are often designed and built to meet conflicting and complex requirements. While mobility is a car's primary function, accomplishing that in an energy-efficient manner and ensuring the safety of the occupants are critical requirements. Automotive OEM's, therefore, are aggressively working on making vehicles lighter without compromising its safety. Meeting such complex requirements often requires solutions encompassing innovative designs, manufacturing processes and multi-material systems. This paper highlights some implementation method of the light weight of the vehicle from the fields of light weight materials, body structural optimization design, molding technology and new connecting technologies.