In vitro and in vivo studies were conducted to evaluate the antagonistic activities off our biological control agents (Trichoderma harzianum, Pseudomonas fluorescens, Bacillus subtilis and Streptomyces spp.) against Botrytis cinerea that cause gray mold of strawberry fruits. In vitro antagonistic study showed that highest reduction% in B. cinerea linear growth was induced by Trichoderma harzianum by 51.3% followed by Pseudomonas fluorescens, Bacillus subtilis and Streptomyces spp. (46.8, 33.2 and 24.6 % respectively). Also, In vivo antagonistic study on strawberry fruits showed that the lowest disease incidence and highest reduction percentage in disease incidence was obtained by Trichoderma harzianum (14 and 76 % respectively)while the highest disease incidence and lowest reduction percentage in disease incidence was obtained by Streptomyce sspp. (22 and 67.3% respectively). On the other hand treatment of fruits with Bacillus subtilis resulted in the highest TSS% (total soluble solids %), titratable acidity and protein content followed by Streptomyces spp., Pseudomonas fluorescens and Trichoderma harzianum. The longer shelf life of fruits was obtained by treatment with Trichoderma harzianum (5.9 days) followed by Pseudomonas fluorescens, Bacillus subtilis and Streptomyces spp. (5.7, 4.3, 4.1 days respectively). Also the lowest fruit weight loses was obtained by Trichoderma harzianum treatment (6.3%) and while the highest was obtained by Streptomyces spp. (9.1%). Trichoderma harzianum, Pseudomonas fluorescens, Bacillus subtilis and Streptomyces spp. showed potent antagonistic activity against B. cinerea that cause strawberry gray mold and reduce the disease severity as well as increase fruits quality characteristics.