Three yeast strains isolated from various sources were tested in its morphological, physiological, and biochemical characteristics. The results were compared with those of 35 standard yeast strains in order to study important taxonomical characteristics for yeast identification and to find out the problem of computer identifying system. Although few characteristics did not coincide with literature data, three unidentified strains were temporarily identified as Saccharomyces exiguus, Candida edax, and Candida membranaefactence. The use of computer identifying system must be accomponied with conventional identification method because of the restriction of data sources for computer system.