[en] We have studied the effects of induced off-diagonal disorder on pump-probe spectra in J-aggregates. Changes of the disorder, i.e. randomness in excite energy of site molecules and inter-molecular coupling within a meso-aggregates, is considered by introducing different random Hamiltonian matrices for two ensembles of aggregates. The theory allows to interpret the intensity-dependent spectra on the J-aggregates as contributed from the combined action of exciton-exciton annihilation and subsequent dynamic disordering processes. The possibility of the transient stage of aggregate ensembles exhibiting lasing due to the excess off-diagonal disorder is demonstrated