Abstract: Models to calculate the coal consumption and heat storage rate of the working medium and metallic materials of a 1 000 MW power unit under trainent conditions were established, based on which, calculation and analysis were performed on the transient test process of the unit, so as to obtain the curves of standard coal consumption rate for power generation corresponding to the heat storage rate and under the heat storage effect during the test, analyze the distributions of heat storage on various heating surfaces at different loads, and to compare the test results with field data. Results show that the total heat storage rate of the unit varies in the same trend with that of metallic materials, and the latter is 1.5-2.0 times of the working medium. Water walls share the largest proportion in the heat storage of working medium, while superheaters share the least. Affected by heat storage, the standard coal consumption rate is at most increased by 3.48 g/(kW·h) during loading up period and decreased by 3.2 g/(kW·h) during loading down period.