The present invention aims to provide novel vectors for plant transformation. The vectors of the present invention are cosmid vectors having a full length of 15 kb or less characterized in that: 1) they contain an origin of replication of an IncP plasmid, but do not contain any origin of replication of other plasmid groups; 2) they contain the trfA1 gene of an IncP plasmid; 3) they contain an oriT of an IncP plasmid; 4) they contain the incC1 gene of an IncP plasmid; 5) they contain a cos site of lambda phage and the cos site is located outside the T-DNA; 6) they contain a drug resistance gene expressed in E. coli and a bacterium of the genus Agrobacterium; 7) they contain a T-DNA right border sequence of a bacterium of the genus Agrobacterium; 8) they contain a T-DNA left border sequence of a bacterium of the genus Agrobacterium; 9) they contain a selectable marker gene for plant transformation located between 7) and 8) and expressed in a plant; and 10) they contain restriction endonuclease recognition site(s) located between 7) and 8) for cloning a foreign gene.