2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/314In this paper, the post-1977 photometric observations of PKS 2155-304 are compiled and used to discuss the variation periodicity. Largest amplitude variations ($ΔU = 1^{m}.5$; $ΔB = 1^{m}.65$; $ΔV = 1^{m}.85 $; $ΔR = 1^{m}.25$; $ΔI = 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.11 pages, 4 figures, A&A (accepted)Astrophysicstext