This papers reports the characteristic of the loan flow in a public libraries' network of metropolis-Tokyo (Ootaku), Nagoya, Kobe. The flow is drawn by smoothing lines that are computed by Iterated Moving Average Method. The data computed is the number of loan summed up each month in the term of 1968〜1985. The flow, especially of children loan, shows to concentrate the fixed level in the long term (approximately above 10 years), although it moves variously in 2〜3 years.
