Abstract: In order to have a concentrated form of energy,the natural gas is liquefied and stored at a temperature of its normal boiling point（112 K）.The demand for the liquefied natural gas（LNG）is growing due to the environmental issues.Recovery of the boil off gas（BOG）generated from the storage tanks at LNG reception terminals as well as during the transportation and production of LNG represents a significant increase of the efficiency of plants.The options for dealing with the boil off gas, including compression and reliquefaction are discussed. It is useful to improve plants safety and effciency while reduce the capital cost in recent years by the addition of the computer simulation,which is a new engineering development tool. Some advanced examples in this field are briefly introduced and a couple of proposals are put forward.