Abstract: A newly developed lattice Boltzmann method (LBM) is used tosimulate the incompressible flow past an oscillating circular cylinder. Boththe vortex shedding modes and fluid forces are investigated. The simulationsare conducted at a relatively low Reynolds number (Re \le 200). Numericalresults show the existence of symmetric/asymmetric modes of vortex formationwhich are confirmed by previous experiments in the near wake, including themode which is not found by some traditional numerical methods. Therelationship between oscillation amplitude and lock-on range is studied, andthe results show that the lock-on ranges increase with the increasingoscillation amplitude. The relationship between fluid forces (lift and drag)and oscillation frequency /amplitude is also studied quantitatively.