The possibilities of learning self-dependence of junior schoolchildren development by means of learning activity are discussed. Theoretical analysis of developing mechanisms of learning activity shows three independant planes of its functioning: mental activity, cooperation, self-consciousness. Present state of learning activity theory and practice allows almost no realization of children's self-consciousness. It hinders full development of junior schoolchildren's reflective self-dependence, being the base of learning ability. The reserves of learning activity ensuring fill value learning ability realization in primary school are marked out.