The utility model relates to a vein clip for clipping rat tails, which belongs to the field of animal experimenting equipment. The vein clip comprises a pair of clip arms (1) that are symmetrically arranged in opposite and a jointed shaft (2). The ends of the two clip arms are fixed together through the jointed shaft (2) and the two clip arms are divided into two parts as the fore arm and the back arm by the intersection part (1.3). Each back arm of the two clip arms is bent in an arc shape towards the outboard. Full of elasticity, the back arms constitute a pressing handle (1.2); the fore arms, however, constitute the tong head of the vein clip (1.4). On the two surfaces at the inboard of the tong head that are opposite each other are arranged a plurality of arc-shaped grooves (1.5) with balanced sizes and shapes and with gullets. The intersection part (1.1) of the two clip arms is only half as long as the pressing handle and is at a 45-degree angle with the major axis. Mutually intersected, the two fore-arms are joined and constitute the tong head. Simple in structure and convenient to use, the utility model can effectively prevent venous returns and keep the veins of the tail full while not hurting the rat tails, therefore, guaranteeing the success rate for vein injections into rat tails.