  Expo 2010 Shanghai China was a successful, splendid and unforgettable event,
remaining us with valuable experiences. The visitor flow pattern of Expo is
investigated in this paper. The Hurst exponent, mean value and standard
deviation of visitor volume prove that the visitor flow is fractal with
long-term stability and correlation as well as obvious fluctuation in short
period. Then the time series of visitor volume is converted to complex network
by visibility algorithm. It can be inferred from the topological properties of
the visibility graph that the network is scale-free, small-world and
hierarchically constructed, conforming that the time series are fractal and
close relationship exit between the visitor volume on different days.
Furthermore, it is inevitable to show some extreme visitor volume in the
original visitor flow, and these extreme points may appear in group to a great
extent.
