Abstract: Place name is complex research object because they contain historical cultural value and express natural features, etc. of a land. Approaching thousands of place name of a land, researchers often take a hard time finding the scientific data to decode them. In fact, many place names have their origin associated with the data of language, culture, history... However, many place names are named by the simple reason. Applying the cultural region theory and the specific research methods through place name research on the Southwestern region from cultural perspective, we discovered that the easy to remember rule dominates strongly the way to name a place. The rule proves that the place name is deeply influenced by the cultural life, habits and behavior of local people. At the same time, this is also one of the research tool to look the origin up and explain the meaning of the place name, contributing to solving a number of the problems that researchers have not found satisfactory scientific findings yet.

Key words: place names, the easy to remember rule, southwestern region, Vietnam, research of geographical names through cultural perspective