An adaptive deflicker method for use in converting a non-interlacing scan data into an interlacing scan data is disclosed. The method includes the steps of receiving a non-interlacing scan data, wherein the non-interlacing scan data includes plural scan lines, proceeding a deflicker operation on an edge line of the non-interlacing scan data, exempting a non-edge line of the non-interlacing scan data from the deflicker operation, and converting the non-interlacing scan data into an interlacing scan data. In addition, an adaptive deflicker filter for use in converting a non-interlacing scan data into an interlacing scan data is also disclosed. The adaptive deflicker filter includes an edge-line detector and a deflicker filter.