Research on DNA transformation of Xanthomonas campestris into Escherichia coli DH5αα using plasmid vector Escherichia coli (pUC19). was carried out. DNA chromosome was isolated using CTAB method, alkali lysis method was used to isolate DNA plasmid. Both of DNA plasmid and chromosome were digested using restriction enzyme EcoRI. Competent cell was prepared with CaCl2 and heat shock method for transformation procedure. The result revealed transformation obtain 5 white colonies, with transformation frequency was 1,22 x 10-8 colony/competent cell. Electrophoresis analysis showed the DNA fragment (insert) in range 0.5 – 7,5 kb. Further research should be carried out to prepare the genomic library to obtain better result of transformant.