THE STUDY aimed to improve the seed germination of cowpea, basil and cucumber by employing chitin and chitosan and to evaluate their effect on some plant pathogenic fungi. The results showed encouragement effect of chitin and chitosan on the seed germination of the three crops. Cowpea has more response to the chitin or chitosan with a significant difference in comparison to the control samples. Their germination percentages were 80% and 87% when treated with a concentration of 1mg chitin or chitosan, respectively. The germination percentages of basil seeds were 91% and 94% when employing 1mg/mL chitin or chitosan, respectively, in comparison to the control sample 76%. On the other hand, the generation percentage for cucumber seeds was 96% for both 1mg/mL chitin and chitosan as comparison to 76% for control sample. The germination percentage was decrease with increase of concentration of chitin or chitosan. The highest percentage of inhibition of pathogenic fungi was 70.58% for Macrophomina sp. for both 4 mg/ml chitin and chitosan. The lowest percentage of inhibition at a concentration of 1mg chitin was 8.23% for A.niger. While in the presence of 1mg/mL chitosan the lowest inhibition percentage was 11.76% for Rhizoctonia solani. It can be concluded that the percentage of germination for each of cowpea, basil and cucumbers decreases with increasing the concentration of chitin or chitosan. The percentage of inhibition of pathogenic fungi was increase with increase the concentration of chitin or chitosan.