A container device with a tightly engaged cover comprises a container; each of at least two lateral walls having a buckling recess; a cover; each of at least two sides of the cover being formed with downward buckling plate; an inner side of each buckling plate having at least one buckle; an upper side of one end of the buckle having a buckling block. When the cover covers upon the container, the buckling plates of the cover will be expanded so that the cover covers the container. The buckles of the buckling plates of the cover will align to and enter into the buckling recesses of the container so that the buckles move downwards through a length; and thus the buckling blocks of the buckles will engage in the buckling recesses of the container; and the container is engaged with the cover by horizontal insertion and buckling effect.