Abstract: A vehicle assembly line has a main line comprising an automated assembly line portion disposed in an upstream portion thereof, a manual assembly line portion disposed in a downstream portion thereof and an automated work line portion disposed in the terminal portion thereof. The automated assembly line portion is formed of train type conveyors which can feed a vehicle body or a work selectively in continuous feed fashion or indexing feed fashion. The manual assembly line portion is formed of trolley type or power-and-free type conveyors which feed the vehicle body continuously. The automated work line portion is formed of train type conveyors which feed the vehicle body in indexing feed fashion. In the automated assembly line portion are included the assembly steps which have already been automated and those which are scheduled to be automated but are to be manually performed for the time being.