A method and an apparatus for determining leakage volume of fluid in transportation pipelines are provided. The method comprises: obtaining the negative pressure wave signals detected by at least two pressure sensors arranged on the pipeline; determining the pressure signal at the leakage location based on the negative pressure wave signals; determining the leakage rate during a leakage period based on the pressure signal at the leakage location according to a leakage model; and determining the leakage volume of the fluid in the pipeline based on the leakage rate and the leakage period. The apparatus provided corresponds to the method described above. By using the method and apparatus described above, the leakage volume of the transportation pipelines can be obtained to help understand the leakage profile of the pipelines and thus reduce losses.