A sliding mode control approach based on feedback lineansat10n IS presented and the control laws designed by it are composed of two psrts. one is feedback linearisablc control and the other is sliding mode control. Using this approcah. a control system is designed for a helicopter vertical flight mode and simulatlon works are done. The results show that the controlled helicopter can track the glven traJectones stably and the proposed control scheme can solve the control problem of the helicopter vertical flight satisfactonly.