Abstract: In this paper we compile some photometric data of quasar 3C273 in radio, millimeter, infrared, optical, ultraviolet, and high-energy bands from 1963 to 2006 taken from literature. We obtain long-term light curves of these data. Using Jurkevich's method and the Discrete Correlation Function (DCF) method, we analyze the multi-wavelength variation periods of 3C273. Our results indicate that (1) there is evidence for certain quasi-periodic activities in all studied wavelengths of 3C273, (2) the results of periods from Jurkevich's method are almost as same as those from the DCF method, and (3) there are possible four intrinsic periodic components for 3C273 in all the wavelengths. There is an 8.0 year period for the radio and millimeter bands; for the infrared, optical, and ultraviolet bands, there are a 2.0 year and an 11.0 year periods; and a 1.0 year period exists for the high-energy band. We briefly discuss possible mechanisms of the periodic variabilities of 3C273. Though many models have been proposed to explain periodic variations of quasars, including the binary black-hole model, slim-disk model, and change of accretion rate, our study indicates that the shock-in-jet model may be the best explanation for the periodic variabilities in 3C273.