Abstract: The original idea of assignment crossover was proposed by Yuchi Nagata and Shigenabu,who used this crossover in TSP problem solving and better result was obtained.This paper illustrates how assignment crossover can be used in image textural classification after modification.In assignment crossover,according to their prositions in the code,all genes in a chromsome is arranged into a circle,a pair of parent chromsomes thus form a pair of circle.With this method,one pair of parent individuals can produce two or three or even more crossover circuits,thus produce more than two new individuals in the new generation.To verify its validity,six objects,namely,bush land,residential areas,rivers,paddy field,drought areas and mountain areas,are grouped into three main types:Ⅰ-bush land,rivers,paddy field;Ⅱ-bush land,residential areas,drought areas;Ⅲ-bush land,residential areas,mountain areas.For each group,a "tuned" mask is generated for purpose of textural classification experiment.