ABSTRACT The staying activity in shopping street has an inseparable relation with the spatial scale of the street. Neither too narrow nor too wide scale of street could bring a good walking experience to pedestrian, so it is especially important to find a suitable scale. Most of the researches are qualitative investigations related to human psychology, and few of them are about underground shopping street. This research made a quantitative investigation on the relationship between the spatial scale of underground shopping street and the staying activity there, defined the concept of staying activity coefficient to quantify the staying activity in shopping street, and used virtual reality experimental method to study the influence of spatial scale changes on the staying activity in shopping street. The research results show that the height and width of underground shopping street as well as the aspect ratio could significantly affect human activity in the pedestrian spaces of underground shopping street. Meanwhile, the most suitable scale of pedestrian spaces in underground street for people to have staying activity is also derived.