We discuss the reconstruction of neutrino flavor ratios at astrophysical sources from future neutrino-telescope measurements, given the knowledge of neutrino mixing angles obtained from terrestrial experiments. With a statistical analysis, we demonstrate that the pion source and the muon damped source can be distinguished at the 3sigma level provided the accuracies on measuring R= Phi(Nu_mu)/ (Phi(nu_e) + Phi(Nu_tau))) and S=Phi(nu_e) / Phi(nu_tau) can both reach about 10%. On the other hand, the above two sources are very difficult to distinguish by merely measuring R alone. We also discuss the effect of leptonic CP phase on such a flavor-ratio reconstruction.
