objective:To screen and identify the interactive proteins of Mps1 and provide clues for the studies on Mps1 function on the chromosome segregation.Methods:The human embryonic cDNA library was screened with pDBLeu-Mps1 as bait plasmid by yeast two-hybrid system.And two Leu+ and LacZ+ positive yeast clones were obtained

which were contransformed to the MaV203 along with pDBLeu-Mps1 plasmid one to one by yeast simultaneous contransformation so as to identify the protein interactions again.The inserted fragments of identiyied positive clones were sequence and analyzed with BLAST in NCBI.Results: Only one positive clone identified one to one yeast simultaneous cotransformation

and the other was negative.The positive clone fragment was MAD1 protein by BLAST analysis in NCBI.Conclusion:To screen and initially identify the interactive protein of.Mps1 this research is a foundation for the study on the founctions of Mps1.