Abstract: Large eddy simulation(LES) computational model was applied to investigate the transient turbulent flow in a continuous casting mold. Reynolds-averaged Navier-Stokes equations(RANS) model was also compared with LES to predict the turbulent flow features. The computation models were validated by ultrasonic doppler velocimetry(UDV) measurement in a liquid metal model,which indicates that the LES model predict much more accurate than RANS model. LES model can capture the large turbulent fluctuation near the jet region. A wobbling stair-step downward jet was simulated,which indicates that the small scale flow dominants this region. Due to the large scale flow structure in the lower velocity region,the asymmetrical flow pattern behavior always exists; the asymmetrical flow disappears with more time averaging.