The study was conducted to investigate the changes in different fractions of phosphorus (P) and the relationship between different P fractions and their corresponding physicochemical parameters during organic wastes composting. There were distinct differences in the concentration of P fractions for the composts generated from different sources, highest in chicken manure and pig manure. The availability P (including water soluble P, Olsen P and citric acid P) declined from 44% to 36% in all composts, except for KW, following the thermophilic phase during composting, while moderately available P and non-available P increased from 48% to 59%. Different P fractions (inorganic P, organic P, Olsen P, water soluble P and citric acid P) were positively correlated with each other. The composts were clustered into two groups in our hierarchical cluster analysis. Conclusively, we suggested an optimized mode of composting based on the characteristics of the P fractions from different raw materials. (C) 2015 Elsevier Ltd. All rights reserved.