Disclosed is a slider assembly for a sliding-type cellular phone. The slider assembly includes a fixing plate formed with a guide section for guiding a linear motion of a sliding plate and fixed to an surface of a main body of the sliding-type cellular phone, a sliding plate guided linearly by the guide section of the fixing plate and fixed to an opposite surface of a cover of the cellular phone, and an up/down positioning member having one end hinged to the fixing plate and the other end hinged to the sliding plate to change a direction of an urging force for pushing the sliding plate from a specific sliding location of the sliding plate. The up/down positioning member includes a first link slider having one end slidably fixed to the fixing plate, a second link slider having one end fixed to the sliding plate and restricted with respect to the first link slider to be slid in a longitudinal direction of the first link slider, a tension spring having both ends fixed to opposite ends of the first and second link sliders, and a restriction member for restricting a sliding length of the sliding plate while guiding a sliding motion of the first and second link sliders.