Too much density of buildings in urban area cause several problems, that varies from environmental influence such as lack of daylighting and natural wind to psychological problems such as oppression to residents and/or pedestrian along the street. In order to reduce those bad effects, building coverage ratio and ratio of building volume to its lot are regulated in Japan, considering the character and activity of the area, however, there has been reported many cases that newly developed 'law-abiding' buildings cause environmental and psychological problem with neighboring residents. Therefore it can be said that new regulation or guideline is highly required to lead adequate density of volume of each building and/or mass of buildings in urban place. And it is also required to know how people evaluate the density of urban area. Thus, we conducted a field research where 134 urban streets between one and eight hundred meters in length and between four and about sixteen meters in width were selected in several cities of Japan, including Tokyo metropolitan. In each street, a staff of local planning office of the area participated this research as investigator and evaluated subjective impression of the street on the whole using SD scales such as oppression from the buildings, spaciousness, brightness, density and preference of the street. The reason of their perceived spaciousness and oppression was recorded freely. They also recorded subjective impression for physical condition of the street such as average height of buildings, volume of space between buildings and amount of cars and bicycles along the street as well as regulations regarding volume of buildings along the street. For the 54 of 134 streets, 3 dimensional data of buildings along the street was also measured in order to calculate other index to explain subjective impressions. As a result, it turned out that regulated rate of volume of building and building coverage ratio have no relation with subjective impression of the street (r<0.5). The average height correlates only with the impression about height of buildings. On the other hand, fractal dimension of 54 street was calculated, which show relatively higher correlation (r=0.5~0.7) with subjective impression regarding spaciousness, oppression, brightness, openness of view and preference of townscape. Thus further research is required in future in order to make better public regulation on the density of townscape, which correspond to people's perception and preference adequately.