An assumption is made on the substantial role of local hydrogen bonds in formation of irregular regions of globular protein polypeptide chains. The statistics of the amino acid composition of irregular regions is examined from this point of view. A statistical analysis of side group-backbone hydrogen bonds is carried out for three proteins: alpha-chy-motrypsin, lysozyme and myoglobin. It is shown that short side groups participate in formation of local hydrogen bonds more often than long ones. Conformations of amino acid residues in the first and the last positions are studied in beta-bends of 9 proteins. It is shown that over 70% of these residues are in conformations corresponding to the formation of local hydrogen bonds of three types: backbone-backbone, side groupbackbone, backbone-water molecule-backbone. Thus, the participation of the cooperative hydrogen-bonding network in stabilization of beta-bends is demonstrated.