In the design of integrator-based filters, there are degrees of freedom in selection of the signal flow graph representing the connection state of the integrator. In this paper, a procedure is proposed for selecting the signal flow graph for a filter with a small deviation from the ideal frequency characteristics, In general, the integrator works ideally near the unit-gain frequency. Hence, in older to realize a filter With excellent characteristics, a guideline is described for selecting the signal flow graph such that the unit-gain frequencies of all integrators used in the filter are close to each other. Since the amount of computation for selection of the signal flow graph becomes enormous even in a filter of low order, an evaluation scale for search is used that can easily estimate the spread of the unit-gain frequencies in individual signal flow graphs. As examples, the signal flow graphs are derived for the fifth-order maximally flat-delay low-pass filter and the third-order amplitude equal-ripple low-pass filter: The validity of the proposed evaluation scale is presented. The effectiveness of the design guideline is confirmed by a computer simulation of the filter made up of MOSFET based on the obtained signal flow graphs. (C) 2000 Scripta Technica.