The influences of the seat suspension on the comfort level, and stability of the bus driver are analyzed using a three-degree-of-freedom (3DOF) quarter-vehicle model. The influences are analyzed through the effects of seat suspension damping ratio ξ se on driver frequency weighted acceleration a w (m/s2) (comfort level) according to ISO 2631:1-1997 standard, the ratio of driver acceleration and gravitational acceleration a/ g (vertical stability). With random excitation according to ISO 8608, considering the same vehicle speed value v (km/h) (in the region of 10 – 20 (km/h)), the decrease of ξ se increases the a w value, this result leads to the reduction of comfort level; Considering the same ξ se value, a w value decreases as increasing v value. With transient excitation according to IRC 99 – 1988, considering the same v value, the smaller ξ se creates the larger a/ g value; Considering the same ξ se, the value of a/ g increases and reaches the extreme in the vehicle speed range 20 – 30 (km/h), outside this speed range the value of a/ g decrease.