Abstract: The experimental model was the counterfort used for the second stage project in Huang-pu new port as prototype, and in specified proportion with it to be made a model.During experiment, the sand was filled behind the model, at the same time, earth pressure was measured. Through the experiments, the following results were obtained:1. Because of the friction effect between the backfill and the wall of counterfort, the measured lateral earth pressure acting on the wall of slab is greatly different from the calculated value by classic theory （Coulomb or Rankine）.2. The friction effect of counterfort ribs causes the lateral earth pressure on the vertical wall to reduce greatly, and the vertical earth pressure on the bottom slabs is also more less than the soil weight pressure on it.3. The measured earth pressure on upper part and middle part of decline plane at rib back is more slightly increased than Rankine's earth pressure.