The expansion of a two-dimensional flow due to the resistance of an oblique wire gauze at setting angles of 30 to 75 degrees has been studied analitically by applying revised TAYLOR'S method.1) Measurements were also made on the expansion of flow in a two-dimensional smoke wind-tunnel, and a agreement between the calculated and measured profiles of flow was found. Additionally, flow observation and velocity-distribution measurement were carried out for a model diffuser equipped with the oblique wire gauze having low pressure drop coefficient.