A lamp is disclosed, which comprises a tubular, an elongate and two end-caps, wherein the tubular body comprises two ends of the tubular body; the elongate light source board is inside the tubular body along a longitudinal direction thereof, and the elongate light source board comprises at least one light source arranged thereon and two ends of the elongate light source board; two end-caps are adapted to seal the two ends of the tubular body respectively, and at least one end-cap is slidingly connected to one of the two ends of the tubular body and fixedly connected to one of the two ends of the elongate light source board. The lamp of the present disclosure can be adapted to temperature changes, and can avoid an overall length variation, and/or a bending deformation in appearance.