In the reign of King Mongkut, the King Bhumibol 4th Thailand must adjust to the modern legal system. This modification is not only a country Thailand. But countries in Asia last fall for the same condition, and is caused by a defect of the law is being used in Thailand. Cannot be used in contact with the foreign Government or trade morning contact at that time. Because of the existing laws, there is some frustration could not be used to solve problems that arise, especially commercial contracts. Mercantile law and law-related techniques, such as the section of tax law are subject to repeated that when these issues compared with these expressly. With a Westerner found and the main Act to solve the problem, and to be able to solve the problem quickly and is accepted by international. Country Thailand must accept the principle of modern Western law came to be used to solve various problems.