This article will explore the roots of law in Malay Muslim Society. In the incident research is a documentary research which objectives of the study are to explore the historical background of the areas which will illustrate the reasons that were responsible for shaping the current Malay society and discuss about the relationship between the local norm and concept of norm which is a central to sociology of law. The study found that three major periods that influence the Malay society. The first was before entering of Hindu into this area, the local people following the custom of tribe; second was the arrival of Hinduism that influenced people’s lives, the Hindu law has been implemented into society at this time and ; third was the entering of Islam into the Malay Peninsula, the Islamic law has been implemented and changed the local people’s beliefs. Malay society is governed by ‘adat’, (a word borrowed from Arabic) and Muslim law in addition to the general law is applicable to all communities. ‘Adat’ as norm in Malay society, being the living law at a certain time in a certain place, adat is elastic and adaptable to social needs and as such not suitable for codification. ’Adat’ is commonly classified into two varieties; the adat perpateh and the adat temengung. The primary purpose of adat is threefold the protection, regulation and preservation of the society.