Water extracts of fresh and 3-month stabilized FYM were examined. The maturation process produced a significant increase in the water-soluble dry matter, organic C and N, pH and EC. No significant difference was found in phenol content, whereas spectroscopic measurements of the extract indicated a higher condensation of organic components with the ageing of the materials. Germination index values, higher in the mature samples, show the persistence in nearly all samples of long-lasting toxicity. Molecular weight distribution in water extract shifts markedly to the high molecular weight side as the stabilization occurs.