The transport of liquified natural gas firstly started at the beginning of the 20th century. The modern transport started with the IMO (International Maritime Organisation) publishing the so called “IGC Code” (The International Code for Construction and Equipment of Ships Carrying Liquefied Gases in Bulk). There are several types of conveying the LNG but most commonly used is by transfering it with LNG tankers. This type of vessels respresent the biggest technological achievement in modern maritime industry. There are two types of LNG tankers which are most used nowadays. Those are LNG tankers with membrane cargo types and tankers with spherical cargo tanks. Both of these cargo containment types have its own advantages and disadvantages. The advantages of the spherical cargo tanks are: better safety and security in the case of collision, grounding or hitting, better conditions in production, they have bigger potential of collecting of boill of gas and smaller sloshing efect. Vessels with membrane tanks have better capacity utilization, they have better visibility from the bridge. When it comes to the cargo operations, the difference in tank cool-down rate can easily be seen. Membrane tanks are much easier to be cooled down than spherical tanks. Based on modern researches, it can be concluded that membrane tanks are much more used than the spherical tanks, and in future, there will be bigger difference in that number.