Thai is a tonal language in which each syllable has a distinctive lexical tone. Central Thai not only consists of Bangkok Thai but also other varieties spoken in various provinces in the central region of Thailand. This study investigates four varieties of Central Thai spoken in Kanchanaburi, Ratchaburi, Phetchaburi, and Prachuap Khiri Khan. The focus is on tone variation. The following are the locations of the study: Amphoe Bo Ploy in Kanchanaburi province: Amphoe Damnoen Saduak in Ratchaburi province: Amphoe Cha-am in Phetchaburi province: and Amphoe Bang Saphan in Prachuap Khiri Khan province. To obtain reliable results, three native informants who were over 40 years of age were selected from each Amphoe (District) to be interviewed on general subjects for at least one and a half hours.