We propose an approach to generating virtual cities that vary dynamically over time, focusing on the layout of artificial elements such as building, roads, and traffic lights. We first define an environment vector as the amount of features reflecting economic and functional activities of city?s residents in each block surrounded by roads. Our method generates virtual cities by deleting and locating buildings from two points of view: building layouts using vectors themselves to generate cityscapes, and time-varying using changes of vectors to vary cityscapes. We demonstrate that our method can represent features and generate various cityscapes that vary over time.