The MM5 model system is used widely in meteorological research and weather prediction operation, but for some unknown reasons, it runs usually on the commercial version of Unix and Linux systems and is unamiable to free Unixlike systems. The transplantation of MM5V3 on the highperformance operating system FreeBSD is introduced in detail. FreeBSD is a free Unix system with particularly high performance. The run time on FreeBSD 6.0 is compared with that on RHAS 4 (Red Hat Advanced Server 4), and it is found that FreeBSD's performance is higher obviously than RHAS'. It is of great significance to operational forecasting.