Abstract: Geomoronology is a science dealing with the morphology of earth surface. Since the morphology of the earth surface is moulded by combined action of endogenic and exdogenic agencies, attention should be focused on the genesis of morphology in classifying morphological types. By using fuzzy mathematics, this paper gives some ma thematic definitions of mountain, hill, plat-form and plain, and further more, establishes indices for the classification of fundamental morphological types based on the maximum membership princi-ple.Two schemes of more detailed classification of fundamental morphological types have been designed that pay more attention to residual steplike geo-morphological structures and, especially, to the developing ones. Also a brief remark on their merits and demerits has been made

Key words: Fundamental Types of Geomorphological Form, Mountain, Hill, Platform, Plain