Cycle fluctuations have been identified which includes real estate investment, real estate consumption, real estate industry and national economy. Spectral analysis is applied in such research based on the statistical data from 1997 to 2010 of Xi’an. The mutual relation could be found between investment and price of Xi’an real estate referring that investment increases with the rise in house prices. Furthermore, a great deal of randomness has been shown in Xi'an real estate consumption which does little effect on the cycle of real estate price indicating real estate market in Xi'an is a seller's market. At the same time, due to the fluctuation cycle of national economy in Xi’an is more than 12 years; the periodic fluctuations of national economy cannot be deduced from the periodic fluctuations of real estate in Xi’an.