Abstract: A multi pipe flow model was established for hypothetical gas liquid solid cylinders under liquid gas countercurrent condition in the packed column. Velocity distribution of the transient section of the entrance and full developed section and the liquid residence time distribution (RTD) at a certain height of column were obtained and also demonstrated by experiments. This model is available when the liquid phase is in laminar flow. It can be directly used to calculate the liquid RTD, the average liquid residence time and the holdup in packed column.