Four basic configurations, block, homogeneous, multilayered, and heterogeneous systems, for tritium breeding in natural lithium water-reflected fusion blankets are compared. A 14-MeV point neutron source is used with a lead multiplier. All the calculations are done in rectangular geometry with the Monte Carlo code MORSE-E and Los Alamos National Laboratory's 30-group neutron cross-section set CLAW-IV in P3 scattering approximation. The homogeneous system gives the best and the block concept gives the lowest tritium breeding, but neither of these concepts is practical for use infusion blankets. Among the practical blanket arrangements, for equal amounts of natural lithium and water, the heterogeneous and multilayered arrangements give almost identical tritium breeding.