This study establishes the mathematical models of MacPherson suspension system including quarter-car for vehicle straight running and half-car for vehicle during cornering, and analyzes how suspension link geometry affects instantaneous center and roll center by using closure equation. Then install a slider at the vehicle body-side connecting portion of the top of the strut and portion of lower control arm so that suspension geometry can be changed by sliding the slider. This paper suggests a variable geometry suspension in accordance with the running condition to reduce the variation of camber angle and the rolling moment of the body. Finally, analyzes the transmission of force of variable geometry suspension and calculated the force to move the slider.