Abstract: Influence of throughput on operation economy of hot oil pipeline is researched based on optimization.For a 529 mm × 8 mm hot oil pipeline with 410.5 km in length, the relationship of optimal throughput scope and transportation costs varied with throughput is obtained and optimal inlet temperature of series throughput points at different process conditions are given.Calculation results indicate that optimal inlet oil temperature appears multiple waveform changes with the throughput, however, the most calculation points tend to the lower limit of searching temperature scope.With increasing throughput, total transportation costs present a downtrend, which shows that higher transportation flowrate is favorable to the improvement of operation economy of the hot oil pipeline.