Abstract: A hinge includes a first hinge leaf unit which has a positioning plate secured to the upper housing of a portable computer, two pivot plates secured to two ends of the positioning plate, and two pivot holes formed through the pivot plates. A second hinge leaf unit is secured to the lower housing of the portable computer and has a pivot pin which extends through the pivot holes. A sleeve is sleeved tightly on the pivot pin and provide friction between the sleeve and the pivot pin to locate the upper housing at a selected position relative to the lower housing. A resisting unit includes first and second torsion springs which are sleeved tightly on the sleeve and which are connected respectively to the pivot plates. When the upper housing is turned downward, the first torsion spring provides a returning force to arrest downward movement of the upper housing and is tightened on the sleeve to allow the sleeve to rotate synchronously with the upper housing.