A frameless liquid crystal display device includes a rear enclosure, a backlight module arranged inside the rear enclosure, a mold frame arranged on the backlight module and mounted to the rear enclosure, and a liquid crystal display panel arranged on the mold frame. The liquid crystal display panel has upper and lower portions mounted to the mold frame through connection sections, each of which includes a rectangular base plate and a trapezoid block. The mold frame forms a trapezoid slot having an open end and a closed end corresponding to each of the connection sections. The connection section is thus receivable through the open end into the trapezoid slot to retain and fix the liquid crystal display panel to the mold frame. The liquid crystal display panel forms a step and a surface decoration is mounted to the step to fix the liquid crystal display panel to the mold frame.