It was shown, that, compared to the south terrains of the region (Irkutsk recreation area), in the suburbs of Bratsk (Irkutsk region) the abundance of taiga ticks is lower and their period of activity is shorter. Also, there are less cases of tick bite in the northern part of the region. However, the morbidity of the human caused by tickborne infections is observed here. In the north of the region prevails tick-born borreliosis, but in the south prevails tick-borne encephalitis. There are shown some dependencies of the abundance, activity and length of epidemiological season on climatic factors. Forecast of human morbidity rate for tick-borne encephalitis and tick-borne borreliosis in Bratsk in 2011 is made.