In this paper , the post-1977 photometric observations of PKS 2155-304 are compiled and used to discuss the variation periodicity .
Largest amplitude variations ( \Delta U = 1 ^ { m } .5 ; \Delta B = 1 ^ { m } .65 ; \Delta V = 1 ^ { m } .85 ; \Delta R = 1 ^ { m } .25 ; \Delta I = 1 ^ { m } .14 ) and color indices ( ( B - V ) = 0.30 \pm 0.06 ; ( U - B ) = -0.72 \pm 0.08 ; ( B - R ) = 0.62 \pm 0.07 ; ( V - R ) = 0.32 \pm 0.04 ) are found .
The Jurkevich ’ s method and DCF ( Discrete Correlation Function ) method indicate possible periods of 4.16-year and 7.0-year in the V light curve .

\keywords BL Lacertae objects : individual : PKS 2155-304-galaxies : variation- periodicity