Since the beginning of Japan's post-war boom her major cities, notably Tokyo, have developed with remarkable speed but relatively little pre-planning and control. So the consequent economic benefits have been accompanied by a level of visual disorder. Public and governmental opinion has therefore recently begun seeking development-control guidelines for improving the visual quality of the urban scene. Some Japanese researchers, building partly on the work of their us colleagues, have responded by trying to identify the most aesthetically significant aspects of the urban visual landscape. This thesis contributes to this search a particularly quantitative approach. It begins with a review of urban-design aesthetic theory concentrating on more recent "psychometric" investigation. It then describes and discusses the main method of the thesis: representation of urban scenes through video stills, computergenerated images, or photographs and the exposure to these representation of groups of sample subjects, and statistical analysis of the subjects' questionnaires responses. Special attention is paid to the reliability with which the aesthetic qualities of a given urban configuration can be generalised from 2-d "perspective" views of it, and to the relationship in subject responses between physical elements like buildings and trees and abstract characteristics like "openness", "enclosure", "age", or "expectant space". These procedures are applied to questionnaires completed by Japanese subjects regarding representations of various Tokyo street scenes, and by largely British subjects regarding contrasting "old" and "new" landscapes in the Hampstead and Milton Keynes areas. Initial investigations suggest that the elements of predominant subjective significance include the proportion of visible sky, the abundance of foliage. This thesis ends by suggesting aesthetic guidelines drawn from these results, considering spatial elements and roles of foliage, and discussing aesthetic assessment for development-control purposes.