Blood flow is influenced by blood pressure, geometric configurations of blood vessel, characteristics of blood itself and so on. Measurement of local blood velocity may be useful in evaluating the properties of blood flow and finding out vascular lesions. In order to measure the local blood velocity, an optical fiber LDV (Laser Doppler Velocimetry) sensor was developed. By chemical etching with a HF-NH_4F buffer solution, a convex lens-like surface was formed on the fiber tip. Laser beam emitted from the fiber tip was focused about 200μm ahead of the tip, where the measuring point was formed. The chemical etched fiber was inserted through a needle into an acrylie resin rube and used as a sensor for pulsatile flow velocity measurement of bovine blood As a result, the local blood velocity of pulsatile flow was successfully measured by this optical fiber LDV sensor.