Characterization of combination of different halftone algorithm is important for assess image halftone quality. A number of researches attempt to develop halftoning algorithm in order to improve halftone image quality. A main factor that influences the combination of AM and FM halftone transformation is the texture difference emerging in the gray level between AM and FM area. The paper purposes to investigate the false texture difference occurred in AM/FM halftone transformation by subjective evaluation. The relationships between the transformations of difference halftone algorithm and texture difference perception are discussed.