Investigations and analyses were done of the data of soil physical-chemical and biological properties of waterlogged paddy fields in seven provinces of South China in an attempt to screen out indices for soil quality assessment of waterlogged paddy fields and build up a minimum dataset for the assessment. Results show as follows. Waterlogged paddy fields differed sharply from non-waterlogged paddy fields and were 26.1%, 11.2% and 12.3% higher respectively in content of soil organic matter, total nitrogen and C/N, and 84.6% lower in available P. The two types of paddy fields did not varied much in content of soil total phosphorus, available nitrogen and available potassium. Besides, the former was 37.6%, 91.5%, 108.1%, 17.0%, 349.5%, 143.1% and 217.9%, respectively, higher than the latter in content of soil moisture, available iron, available manganese, available zinc, Fe²⁺, Mn²⁺, total reducing substance and significantly or 43.8% and 25.2%, respectively, lower in soil microbial biomass carbon and phosphatase activity. However, the former was significantly or 21.2% higher than the latter in soil catalase activity, but did not differ much from the latter in invertase activity. Other than those, the former had a nematode population density of 301.9±78.5 individuals 100g dry soil^-1, which was significantly lower than that in the latter. By means of paired sample T test and principal components analysis, it was found that the minimum data set (MDS) for soil quality assessment of waterlogged paddy fields should encompass the following six indices, that is, pH, total nitrogen, available manganese, Fe²⁺, CN ratio and nematode population, which are significantly lower than their corresponding ones for the non-waterlogged paddy fields. All the findings in this study may be of some important significance to soil quality assessment, soil amelioration of cold waterlogged paddy fields.