The topic of this thesis is Impact of family stress on early and preschool children and it will be discuss about various negative experiences that create stress in the family. Early childhood is a time of big and rapid changes, when the architecture of the developing brain is the most open to the infulence of relationships and experiences. Relationships with caring, responsible adults and early positive experiences will build a strong brain architecture in children. Significant stress because of the constant difficulties or threats (e. g. exposure to violence, extreme poverty or abuse) disrupts the biological foundations of learning, behaviour and health. with life consequnces. This paper will explain the mental health of children and point out that it is necessary to devote more attention to early mental health problems that occur in young children because they can disrupt the typical patterns of development of the architecture of the brain and impaired ability to learn, or are at risk of cognitive and mental health problems. Family stress disrupts family relationships and affects the child if parents do not have appropriate strategies to affront with stress. The aim of this thesis is to point out the importance of creating a positive environment for the child so that the child can develop unhindered.