A portable computer includes a base, a display module, at least one support element and at least one sliding assembly. The display module comprises a connecting end and a display face. Each support element comprises a first end pivoted on a portion of the display module other than the display face and a second end pivoted on the rear end of the base. Each sliding assembly comprises a slide rail disposed at least in the second area and a sliding element combined with the connecting end and moving along the slide rail. Each sliding element includes at least one sliding auxiliary structure for decreasing friction during sliding.