Three laboratory experiments were conducted during 2008 to evaluate the antifungal activity of some plant extracts at different concentrations against pathogenic fungus Fusarium oxysporum. Plants of Artemisia herba-alba, Achillea santolina and Saliva aegyptiaca were collected from central region of Iraq. The plant materials were dried under temperature and laboratory condition , then ground by a blender. Plant extracts were prepared and different concentrations of 0, 125, 250, 500 and 1000 ppm were added to PDA medium for antifungal activity tests against the fungus growth . The results obtained showed that different plant extracts and concentrations caused various antifungal activity. Plant extract of Artemisia herba-alba_showed weak inhibition activity on fungus growth even at highest concentration of 500 and 1000 ppm which produced 15.2% and 17.7% inhibition of fungus growth, respectively. Similarly, the pathogenic fungus F. oxysporum showed no obvious response to Achillea santolina extract with all concentrations tested. Concentrations of 500 and 1000 ppm caused 11.8% and 20.5% inhibition of fungus growth, respectively which was almost in agreement with the effect of A. herba-alba at same concentrations. Plant extract of Salvia aegyptiaca , however , produced greater fungus growth inhibition as compared to those of Artemisia herba-alba and Achillea santolina especially at higher concentration . The concentration of 125, 250, 500 and 1000 ppm caused 17.2%, 26.5%, 40.8% and 49.1% inhibition of fungus growth, respectively. The present results indicate that plant extract of S. aegyptiaca appeared to be more effective as antifungal growth inhibitor than other plant extracts tested. It was concluded that antifungal activity of S. aegyptiaca extract could be used in biological control which need more investigation for this evaluation.