Abstract: A chassis includes a main box body. The said main box body includes a back panel, an upper cover panel, a lower cover panel, a left side panel and a right side panel connected with each other. An upper single panel slideway and a lower single panel slideway are provided in the main box body for fixing single panels. A fan is provided on the top of the main box body. A power distribution unit is provided on the bottom of the main box body. A connection portion is provided in the chassis for connecting the fan and the power distribution unit. The connection portion is a groove provided from the top to the bottom of the side panel for holding acable or two holes provided on the upper and the lower locations of the side panel for guiding the cable.