Raindrop size distribution (DSD) retrieval algorithm for an X-band dual-polarization weather radar is proposed. In this algorithm, DSD range profile is estimated to match the dual-polarization measurements, where the forward and back scatters are formulated simultaneously to avoid the two-step process of attenuation correction and DSD retrieval. For the optimization, the iterative maximum likelihood is applied, in which a posterior PDF of DSD parameters are calculated and then extended to radar network environment. Estimation accuracies of log(N_w) (N_w; mm^-1m^-3) and D₀ (mm) derived from single-radar numerical simulation are a mean bias (MB) of -0.02 and a standard deviation (SD) of 0.23, and an MB of 0.01 and an SD of 0.10, respectively.