A telecine conversion method detecting apparatus which determines that an input video signal is a telecine converted video signal generated from a movie film in accordance with a 2-3 pull-down method when detecting that an inter-frame difference accumulated value of a current field of the input video signal is equal to or less than a threshold value for still field determination, that each inter-frame difference accumulated value of four fields preceding the current field is equal to or greater than a threshold value for motion field determination, and that the inter-frame difference accumulated value of the current field is less than each corrected value calculated by multiplying each of the inter-frame difference accumulated values of the four preceding fields by a predetermined coefficient.