Visual perception is vital for people’s spatial experience. Many factors correlate with visual perception including spatial size, material, color, and geometry. However, studies systematically exploring spatial size are sparse, especially with regard to the interactions between the factors of spatial size. In this study, 15 indoor virtual reality environments with five widths and three heights were used to examine the influence of spatial size on visual perception. The study adopted a preference survey as the primary data-gathering tool assessed using a factorial analysis of variance. The results revealed that the influence of width and height on peoples’ preference levels for the indoor virtual reality environments was significant. However, the preference level did not always improve with an increase in width and/or height. A certain spatial size may enhance or contradict visual perception, but changing the width and height does not always exert a significantly different effect on the preference evaluation for the virtual reality environment. This study proposes a new idea that an indoor virtual environment that can adjust its spatial size can be used as a supplement to improve the quality of a real environment.