This book presents the physiological qualities of the varieties of Creole rice seeds from the municipalities of Cachoeira Grande and Morro - MA through germination and vigour tests carried out at the Seed Analysis Laboratory belonging to the Agricultural Sciences Centre of the Phytotechny and Plant Health Department at the State University of Maranhão with the aim of finding the most productive Creole variety. This book provides the reader with more detailed information about the research and the results we found with these peculiar varieties.