With a practical application on the large-scaled crude oil unloading terminal in Guangdong province,this paper systematically analyzes the influence of some factors on the throughput capacity of large-scaled crude oil unloading terminals.For a crude oil ship,the whole process involving reaching the anchorage,approaching the channel,berthing operations,unloading operations,leaving berth operations and ships departure to shelter from wind and wave is modeled in detail.Meanwhile,considering the influences of tides,wind-waves included fog,channel control rules and other factors on the above mentioned process,we establish the model to simulate the port & channel system of large-scaled crude oil unloading terminals.The rational throughput capacity of a terminal is demonstrated scientifically based on the port service level performance index.All the investigation may serve as reference for the construction of large-scaled crude oil terminals.