Pseudomonas fluorescens is an effective bacteria used in biocontrol agent for various soil borne plant diseases including plant parasitic nematodes. The aim of this study is enhancement the biocontrol effect of this bacterial strain by introducing chitinase gene(s) from Serratia marcescens. A DNA fragment containing the gene(s) were inserted into pGEM vector to construct a new plasmid, which introduced into P. fluorescens. Restriction enzyme digestion and chitin plate culture confirmed that the improved P. fluorescens is containing a functional chitinase gene(s). Bioassay comparative results among P. fluorescens wild type, Serratia marcescens and transformed P. fluorescens which conducted in screen house experiment indicated that transformed P. fluorescens had increased effect against plant parasitic nematodes (Meloidogyne incognita).