Abstract: This paper discusses thetask and significance of the biomechanics with respect to animal flightand swimming as well as importantscientific problems of biomimetictechnology in applications. Some aspects relevant to the externalbiofluid dynamics including scientific problems, present research status, and achievements in China are briefly reviewed. We mainlysurvey the following issues relevant to the external biofluid dynamics: Grayparadox and the measurement of drag force of fish swimming, characteristics andmechanisms of fish manoeuvrable swimming, the interaction of fish body and thesurrounding fluid, unsteady flow controls and power requirements of insectflight, flexible and optimizing aerodynamic characteristics of insect wing,the measurement of kinematic and kinetic quantities for insect and fish freemovements.