Proteomic studies of some human tissues and organs (skeletal muscles, myometrium, motor zone of the brain, prostate), and also cultivated myoblasts revealed 41 proteins, in which the presence of certain variants of amino acids (“conflicts”) was recognized at several “conflict” positions. Among the 93 registered “amino acid conflicts”, seven cases represented the results of the protein polymorphisms caused by corresponding substitution of individual amino acid. Proteomic analysis of prostate proteins revealed two isoforms of a prostate-specific antigen, formed due to alternative splicing. Thus, our results have shown that employment of the proteomic technologies may characterize various types of biochemical polymorphism in many human proteins.