A lamp device is provided with a string having a plurality leads, a plurality lamp sockets and a plurality bulbs. A plurality of posts having a tip portion at one end and a fastening portion at the other end and a connecting plate with an upper plate portion connected to the fastening portion and a lower plate portion connected to the tip portion are provided. The top portion has two tips providing a fork forming a recess on the lower plate portion of the connecting plate. The fastening portion has two protection walls, each protection wall having an extension piece formed thereon, each extension piece having an upper lug and a lower lug providing a recess between the upper lug and the lower lug, the tip portion being able to be inserted into the ground or into something loose to support the lamp device. A plurality of lamp covers are provided. The fastening portion of each post is connected to an associated lamp socket of the sockets, with an associated bulb of the bulbs and an associated one of the covers or to the tip portion of another post to form a lengthened post. Each lamp cover has one of various patterns formed thereon, each lamp cover has a bottom with a fastening portion for securely connecting the lamp cover to the fastening portion of the post or to the associated lamp socket. The associated bulb is disposed substantially centrally inside the cover whereby reflection or deflection of light by the cover results in various decorative patterns as the bulb when the bulb is lighting. The lamp cover has a hollow portion inside defining a hole. The hole cooperates with the fastening portion, with the fastening portion providing a clamping along the edge of the hole.