Singlet and triplet excitonic energy migration in mixed-stack charge-transfer crystals of tetracyanobenzene-biphenyl (TCNB-B) doped with anthracene (10(-4)-10(-2) M/M) have been studied within temperature range 5-300 K by using optical, spectroscopic and kinetic techniques. It has been found, that the motion of excitons is thermally activated with the activation energies of 450 +/- 60 and 550 +/- 60 cm (-1) for the singlet and triplet excitons, respectively. The later value differs from the activation energy in undoped TCNB-B crystals (where it is 360 +/- 60 cm(-1)) and suggests that doping with anthracene perturbs the host crystal lattice.