Abstract: The cake of oil-extracted Amygdulus pedunculatus kernel,which is rich in high-quality proteins,is a new good resource of vegetable proteins.The objective of this paper was to study the preparation technology of isolated protein from the cake of oil-extracted Amygdulus pedunculatus kernel.Alkali-extraction-acid-precipitation method was used to prepare isolated protein with cold pressed Amygdulus pedunculatus kernel cake as raw material.On the basis of single-factor tests,the technological conditions for the extraction of Amygdalus pedunculatus kernel protein were optimized by response surface design.The isoelectric point of the protein from Amygdalus pedunculatus kernel cake was determined by contrasting the protein contents of supernatants after protein precipitation atdifferentpH values,thusthe optimum pH value forisolating the protein by acid-precipitation was established.The results showed the effect of factors on the extraction ratio of Amygdalus pedunculatus kernel protein was in the sequence of liquid-solid ratio,extraction pH and extraction time and the optimal conditions were:liquid-solid ratio of 20:1,extraction temperature of 41.6℃,extraction time of 78.8min and pH of 9.1.The optimum pH for acid-precipitation of isolated protein was 4.1,which also was the isoelectric point of Amygdalus pedunculatus kernel protein.Under the above conditions,the once extraction rate of Amygdalus pedunculatus kernel protein was 70.2% and the yield of isolated protein products was 36.7%,in which the protein content (N×6.25) was up to 92.3%.It was concluded that both the yield and the protein content of the isolated protein products prepared by alkali-extraction-acid-precipitation method were higher under the optimal conditions.Furthermore,most of the gydalin was removed during the processing,which implied that the high-quality protein products were obtained.