The influence of different heat treatments(59,62,65,68℃,0~9min) on the composition,solubility,emulsifying properties and free sulfydryl content of egg yolk plasma and granules were studied.Results showed that γ-livetin in egg yolk plasma and part of high-density lipoprotein(HDL) in egg yolk granules denatured during heat treatments.The effect of heat treatments on the solubility of egg yolk plasma was more significant than egg yolk granules.The influences on emulsifying properties of egg yolk plasma and granules by moderate heat treatment were not significant.When egg yolk plasma and granules were treated at 68℃ for a long time,the emulsifying activities were significantly decreased and emulsion stabilities were increased.No regular variations of free sulfydryl content of egg yolk plasma and granules were found during heat treatment.