Candida species employed in this study were isolated from patients with acute lymphoid and myeloid leukemia. Blood, sputum or oral swabs were taken from those patients. A total number of (100) patients was included in this study, 42% of those patients were with oral/respiratory, or blood infection with Candida spp., the major species was Candida albicans (31 out.of 42) i.e. 738%. Eight of those leukemic patients out of (100) developed systemic candidiasis as detected by precipitation reaction and blood culture. The antigen prepared from cytoplasmic fractions of C. albicans cells. While, blood culture gave only parallel results in two cases. C. albicans cell wall was studied by SDS-polyacrylamide gel electrophoresis and gel filtration chromatography. Three fractions with many bands of molecular weights ranging from 94000 to 28000 Dalton with many other faint bands were obtained. Crude cell wall showed (8) clear bands with molecular weights .ranging from 90000 to 18000 Dalton with additional faint bands with different molecular weights. Proteinase enzyme of C. albicans was purified, characterized, Studied for its ability to proliferate blood lymphocytes, antibacterial activity were determined, finally we tried to use this enzyme for passive immunization of laboratories animals. The enzyme was purified by using CMI-cellulose ion-exchange chromatography then with sephacryl S-200 )column chromatography as first step and then with sephacryl S-200 column chromatography as second step of purification and for determination of the enzyme molecular weight by using different standard proteins, the molecular weight of the enzyme was estimated and found to be 57676 Dalton. Stability of proteinase enzyme and its activity at different pH and temperature were studied in details. Antibacterial acitivty of proteinase enzyme against E. coli, I Klebsiella spp., Lactobacillus spp., Enterobacter spp. and Pseudomonas aeruginosa was studied. The almost sensitive bacteria was Lactobacillus spp.followed by Klebsiella spp., then Enterobacter spp., Finally, E. coli. pseudomonas aeruginosa is the almost resistant one. In this study proteinase enzyme as an antigen has no effect on lymphocytes proliferation or to suppress this activity (p<0.05). The most important disclosure of the activity of proteinase enzyme to stimulate production of antibodies. These antibodies could protect animals from infection with C. albicans.