"In the context of the ever changing urban landscapes of our era, it seems to be well recognized that one of the major issues of environmental perception is perceptual complexity or diversity. The desired level of complexity in visual scenes in the city has been mentioned often, but the degree of complexity rarely has been quantitatively defined. This paper presents a method of measurement for two different aspects of visual complexity in the environment: one is visual diversity of a scene around a view point, and the other is a sequential change when the perceiver moves through the environment. A personal computer program was developed to assess an array of visual surfaces which surround an observer. The visual surfaces in the environment are first divided into basic units (components) on the basis of their meaning for basic human behavior or 'affordance". The units include such surfaces as pavement, earth, grass, trees, building and sky. The program then assesses surrounding scenes by numerous scanning (visual) lines radiated from a station point in all directions with equal density. Next, it creates a chart which shows the array of visible surfaces of various components. The resulting chart is divided into cells according to azimuth (72 partitions) and altitude (29 partitions) of the direction of scanning lines. Thus it has a total of 2,088 cells, each of which represents one of the components. With this data, the program then calculates number of partitions which divides two neighboring cells of different components. This measure is expected to describe the complexity of the visual scene surrounding the perceiver. As for the sequential variation, the charts obtained by assessing two consecutive station points along the path are compared, and the number of changed cells of the same position is calculated. n order to examine quantitative relations between human responses on the one hand, and the measures obtained by the program on the other, landscapes of nine different housing neighborhoods were assessed. A sequence of scenes along a typical path in each of the nine housing sites was presented to the 43 subjects by a series of slides taken at ten consecutive points each ten meters apart. The subjects were asked to rate each landscape using a bipolar adjective pair of "monotonous vs. varied". The data from this empirical study revealed that the complexity of a place can be well explained by the measures obtained by the program. Although it may require some effort to establish the data of the site for the program, once we have the data, it is quite easy to assess the visual state at any point in a proposed environment. If an environmental designer uses computer aided drafting , the data is obtained without extra effort, the designer can easily and interactively use this program in the design process."