Why do tourists want to travel? What is the significance of tourists’ spatial behavior? This paper attempts to answer these questions from the perspective of mobility and modernity, following the argument that mobility is the path to, and a symbol of modernity. This paper hypothesizes a situation whereby “travel has become the modern people’s daily life under the background of mobility.” It discusses the significance of tourists’ spatial behavior from the separate stages of life-world and travel-world to the stages of united life-world and travel-world against the background of mobility. The paper then proposes that “tourists’ spatial behavior is the way for man to become a modern man” and highlights the significance of tourists’ spatial behavior in “becoming a modern man” from three aspects: starting point, symbol, and identity. In response to Gong Pengcheng’s view that the significance of travel lies in “animal instinct” and integrating this notion into the macro framework of the generation and evolution of “human civilization,” this paper, from the perspective of mobility and modernity, attributes the significance of tourists’ spatial behavior to “modern human instinct” and puts it in the framework of the generation and evolution of “modern civilization.”