Based　on　a　common　biological　phenomenon　-　homologous　recombination　-　a　novel　method　was　developed　by　transferring　chromosome　DNA　fragments　extracted　from　multiple　donor　cells　into　a　host　strain.　Through　this　method　of　transferring　DNA　fragments,　foreign　DNA　fragments　are　introduced　into　one　host　cell　and　multiple　positive　traits　from　multiple　strains　may　be　integrated　into　the　host　strain.　We　first　confirmed　its　feasibility　in　both　prokaryotic　and　eukaryotic　cells　by　selecting　reverse　mutants　to　prototrophy　from　auxotrophic　strains　through　receiving　chromosomal　DNA　fragments　of　wild-type　parental　strains.　We　then　applied　this　method　to　Saccharomyces　cerevisiae　to　improve　its　ethanol　and　temperature　tolerance.　We　introduced　donor　chromosome　DNA　fragments　from　different　S.　cerevisiae　strains　with　improvements　in　ethanol　or　temperature　tolerance　into　a　common　strain　S.　cerevisiae　and　obtained　a　strain　with　much　superior　ethanol　and　temperature　tolerance.　The　results　showed　that　the　Transferring　DNA　Fragments　method　provides　a　new　way　for　strain　breeding.