Abstract: A sheet feeding apparatus includes a sheet feeding channel, a sheet feeding structure, a sheet stopping structure, plural sensing arms, an optical sensor and a controller. By the sheet feeding structure, a paper sheet is fed into the sheet feeding channel. The sheet stopping structure is used for stopping the paper sheet from being moved forwardly. During the process of feeding the paper sheet, the plural sensing arms are pushed by the paper sheet to be rotated. According to the rotating statuses of the sensing arms, the optical sensor issues different signals to the controller. According to these signals, the controller will control the operations of the sheet stopping structure and the sheet feeding structure, thereby correcting the skew condition.