In this paper we study the problem of weak processes regulating the activity in primary school children with learning disabilities. The study was conducted on children with severe learning difficulties (from 1 to 4-5 grades), and on the sample of first graders with varying success in learning. The main method was Luria’s neuropsychological assessment adapted for 5 – 9 years old children (Akhutina et al., 2008/2012; Polonskaya, 2007). It is shown that the children of both samples can be divided into three groups according to the function states that regulate the activity: children with hyperactivity-impulsivity disorder, children with fatigue and low tempo characteristics, and children without a significant deficit of the unit I functions. The close relationship of unit I functions deficit and school performance was demonstrated. It was revealed that children with hyperactivity disorder characterized by severe weakness of programming and controlling processes and visual and visual-spatial functions (with weak left analytical hemisphere and right-hemisphere which is responsible for holistic strategies of processing information). Children with sluggish cognitive tempo are characterized by less pronounced weakness in programming and controlling functions and also by prominent audioverbal and kinesthetiс difficulties (weakness of the left hemisphere which is responsible for analytical strategy of processing information). Various components of higher mental functions in children with learning disabilities show uneven age dynamics: from 1 to 4-5 grade the symptoms of fatigue, low rate and kinesthetic difficulties practically do not manifest positive dynamics in contrast to all other components of the higher mental functions.