Abstract: The tourism flow is a series of economic and social effect caused by the concentration and diffusion of tourists in spatial area,and it is the nerve center and vessel of tourism system.Former studies on tourism flow are mostly concentrated on realistic tourism flow instead of virtual tourism flow,and data acquisition is based on questionnaire or statistical data of scenic spots which has limitations.The paper,supported by Baidu index and based on the substantial and accurate data,constructs O-D virtual tourism flow matrix to conduct research on the characteristics of regional virtual tourism flow and uses the Geographic Weighted Regression(GWR）model to analyze the influencing factors of virtual tourism flow in different cities from two aspects of inflow and outflow.The following results can be obtained:(1)The virtual tourism flow in the Yangtze River Delta is unevenly distributed and has strong mobility,forming a radial network with Hefei,Nanjing,Suzhou,Hangzhou and Shanghai as the core nodes.(2)The number of A-level scenic spots,accommodation and catering industry employees and highway mileage can better explain the distribution of the inbound virtual tourism flow.Among them,the A-level scenic spots have the most significant impact on the inbound virtual tourism flow.The development of accommodation and catering industry has a driving force to the inbound virtual tourism flow in northwest of the Yangtze River Delta,and the mileage of highways has the least impact on the inbound virtual tourism flow throughout the Yangtze River Delta.(3)Private car ownership,total retail sales of consumer goods,and Internet broadband user access have a strong impact on outbound virtual tourism flow.The economic factor represented by the total retail sales of consumer goods is the decisive factor for the outbound virtual tourism flow.The more developed the economy is,the more people want to travel.They are also more willing to use the network to capture tourism information flow and pursue high-quality tourism travel behavior.