Four isolates of Pseudomonas species showed inhibitory effect against four important soil borne pathogenic fungi (Fusarium oxysporum, Rhizoctonia solani, Seleratium rolfsii and Pythium altimum), the causal organisms of damping-off and root rot of sugar beet diseases and against one of the important foliar diseases (Cercospora leaf spots) caused by Cercospora beticola.             The bacterial biocontrol agents (P. fluorescens, P. cepacia, P. aureofaciens and P. putida) showed the highest mycelial reduction from 60 to 20% in laboratory experiments. In greenhouse tests, all isolates were effective comparing with control (without bacteria). Application of Pseudomonas spp. as seed dressing and infestation of soil were used and also spraying as suspension with these bacterial bioagents on the foliar of sugar beet plant to control the causal organism of cercospora leaf spots disease. A density of 7 x 10⁹ cells per ml reduced damping-off percentage when seeds were sown in artificially infested soil with one of the pathogens.             The objective of this research were to study the effect of using the bacterial biocontrol agent against damping-off, root rot and cercospora leaf spot diseases of sugar beet (Beta vulgaris, L.) and to study the effect of spraying with the bacterial suspension on the foliar to reduce or control cercospora leaf spots disease especially.