Swine manure was mixed with corn stalk powder as a bulking agent, and the mixtures were amended with flyash at 0, 2.5%, 5.0%, 7.5% and 10% and composted for 90 days. Addition of flyash raised the pH value of the swine manure compost throughout the composting period, but significant inhibited the rise of electricity conductivity during the later period with the ratio of flyash increasing. C/N ratio decreased according to composting time, whereas total N showed an opposite trend for all treatments except 10% flyash was amended. There was no significant loss ofNH+4-N during the thermophilic phase by ash amendment. While, addition of flyash also inhibited the nitrification process as indicated by the lower soluble NO3-N content in ash-amended swine manure composts but had no effect on TP and TK increasing. The GI and germination rate of potherb mustard (Ardisiasquamulosa presl) seed increased with composting time, while the root growth was significant inhibited when flyash was amended and the germination rate indicated that flyash amendment did not affect compost maturity in 90 days composting.