There is a great disparity among the harbor design code of China and BS 6349-4: Maritime Structures and OCIMF Mooring Equipment Guidelines associated with the berth length of open sea terminals: the berth length provided by Chinese codes is longer. A basin experiment is carried out to study the influence of the berth length of open sea terminals on the mooring force and ship movement. The hydrological conditions include wave, tide and wind; the test ship model is a typical 30 000 DWT oil tanker; 3 berth length arrangements are considered in this test. The experimental results indicate that by reducing the berth length and homogenizing the cable length, the mooring force tends to be uniform and the ship movement related with horizontal restrain can be reduced.