Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
; CCAST, World Lab, Beijing 100080, Peoples R China
Contributions of fermion loops, W-boson loops and their sum to the high energy gammagamma --> gammagamma scattering total Cross sections (\cos theta\ < cos30&DEG;) are calculated by analytical expressions of γγ --> gammagamma scattering amplitude. These contributions may be observed in the future photon linear collider and may be used to test standard model. The contribution of fermions' loops is a half of that in R.K. Arphlus and M. Neuuman's paper (Phys. Rev. 80 (1950) 380; 83 (1951) 776).