In a collapsible supporting device for a portable computer, a pair of base members and a pair of interconnecting members are connected pivotally to a coupling seat. A pair of supporting members are coupled to the interconnecting members, respectively. The supporting device is operable to move from a folded position, where the base members and the interconnecting members are disposed parallel to each other, to a supporting position, where the interconnecting members are disposed between the base members, where a stopping block on each base member abuts against a front portion of the computer, where a desired angle is formed between the interconnecting members, and where each supporting member is disposed uprightly and has an abutting end disposed higher than that of each base member and abutting against a rear portion of the computer.
