Long-time researches of Lake Baikal have confirmed essential warming of its climate in second half XX centuries, the most expressed in the winter season. This factor has led to appreciable augmentation of quantity of wintering birds - with 81 to 121 species. This process is most expressed in the South Baikal climatic district which unique conditions promote formation of mass «cold» wintering grounds at a series of bird species of various regular bunches. From the south Baikal the quantity of wintering species decreases for the north of the lake. Their basis is compounded by settled and wintering species though the quantity forcedly and casually wintering of bird species has considerably increased now.