Investigations on the structure and character of spider communities of the single rice cropping field were carried out in Jiangpu County, Jiangsu Province and Tongling City, Anhui Province during 1987-1988. The spider communities comprised 45 species, belonging to 25 genus in families. The main components of the communities were Ummeliata insecticeps, Erigonidum graminicolum, Priata subpiraticus, and Pardosa pseudoannulata. The diversity and evenness index in rape field was higher than that of other winter crop fields. The diversity index showed that there were two obvious peak during the rice growth period. The first peak (3.68531) occured on 24th, July and the second one (3.96823) appeared on 11th, September. The diversity, evenness and abandance index of the mid-late stage of rice growth and the late planting rice fields were higher than that of early stage and early planting rice fields, while the dominance index was in reverse. The community stability of late planting rice fields was better than that of early planting. The similarity of spider communities was closely related to transplanting day of rice and it can be grouped together according to similar transplanting date by ordinal arrangement and Fuzzy Cluster. The similarity in the same area and year was more remarkable than that in different areas and years.