It has been studied the activity of CFUf of human bone marrow in orthopedic and haematologic patients. The architectonics of large colonies was investigated too. The cloning efficiency of CFUf of patients with funnel chest was 55,4±2,2 among 105 bone marrow cells and of patients with congenital hip dislocation 27,4±3,0 among 105 cells. There was the cloning efficiency of CFUf from 0 to 240 among bone marrow cells in haematologic patients. It has been shown that large colonies consist of the surface monolayer of fibre-blast's cells, the products of cell's metabolism, some adipositic cells and fibroblasts which form the primitive structure of circulation.