A locating device for a slide is to install a locator at the rear end of an outer track. The locator is formed by blanking and bending a flexible metal piece, and its main body is to form a U-shaped base in cross-section with two vertical edges extending upwardly from respective sides. The base of the locator is formed with holes and riveted to the outer track. The base further extends a portion upwardly from the rear end to form a vertical plate comprising a pair of hooks extending from the top end of the vertical plate towards the front end. The hooks engaging with a buckle device of an inner track or of a middle track secures the inner track and the outer track together.