Abstract: The synthesis effect of manganese and finish rolling temperature on high nitrogen vanadium microalloyed steel was investigated by testing the mechanical properties,examining the microstructure and the precipitation of carbo-nitride by use of SEM and TEM.The results show that the high manganese content can compensate the unfavorable influence of high finish rolling temperature on fine microstructure,while the high finish rolling temperature can eliminate the unfavorable influence of high manganese on precipitation strengthening,wherefore the high manganese as well as high finish rolling temperature is good at fine microstructure and precipitation strengthening.