Experimental studies show depressive behavior of rats caused by hypothyroidism and anti-depressive effect of thyroid hormones. The present study analysis changes in emotional state of the progeny of rats suffered from iodine deficiency of different severity before mating and during whole period of gestation. The basic diet with low content of iodine markedly decreased animal's motor activity and that was clearly demonstrated in open field testing. More pronounced changes in open field behavior was observed in group of animals with more restricted iodine diet (addition of KClO(4) to the basic diet) -- animals show significant decrease number crossed squares, number of entering into central squares and vertical standings, and increased frequency of gumming. Addition of the iodine to the diet prevents development of the mentioned changes.