Organizational psychology is a field known to us lately, which asseses individual behaviour in organizations. But much knowledge of human behaviour in organization derives not from pure behavioural research studies but from management analysis associated with changes in management policies and practicies that have been in progress since the 1930.S. As such techniques as delegation of authority, management by exception and cost effectiveness, began to prevade management thinking, the significance of people characteristics came into focus. To apply these approaches, it became necessary to understand human behaviour, both qualitatively and quantitively. As a first step participative management crept in to replace autocratic management but this appeared less capable of maximising employees as it was under autocratic management. This fact coacertrated the attention on motivation as the best way of maximising staif and improving performance. It means that behavioural sciences gave solution to some of the management problems and began to study individuals and groups and identified their psychological needs.