Linear optical responses of large PPV (poly(p-phenylenevinylene) aggregates have been investigated numerically using the linear-scaling (LDM) method. The semiempirical CNDO/S (Complete Neglect of Differential Overlap in Spectroscopy) Hamiltonian is adopted in the calculation. Distinct intermolecular excitations have been identified, and their characteristics have been determined by examining real-space electron-hole pair distribution. Relevance of our results to the experimental observation is discussed.