Plasmid DNA with foreign chitinase gene was introduced into water melon lines by the approach of pollen-tube pathway. Transgenic plants were obtained by basta screening and PCR amplification.Three transgenic lines with improved resistance to Fusarium wilt were selected by natural occurrence and artificial inoculation. The results indicated that the chitinase had certain inhibition effect on Fusarium oxysporum, and the method of pollen tube pathway could be successfuly used in watermelon transformation.