Abstract: DNA from Escherichia coli was successfully introduced into spores of strain Tü 4128 by intergeneric conjugation through bacteriophage φC31 att/int system. The transconjugation frequency on ISP4 medium with 80 mmol/L MgCl2 was significantly improved up to 73×10-3 per recipient cell under optimized mating temperature of 37 ℃. Southern blot analysis revealed a single chromosomal attachment site on the chromosome of the recipient strain. The DNA sequence of the integration site was determined and shown to be conserved. An efficient intergeneric conjugation between Escherichia coli and strain Tü 4128 was successfully achieved by condition optimization.