All visitors to Thailand must be in possession of a passport valid at least 6 months from the date of entry. Nationals of most countries and territories are permitted to stay 30 or 90 days without visa.Nationals of some countries (including China, India, Romania, Bulgaria, Ukraine, Lithuania and Latvia) can obtain “Visa on Arrival” at the point of entry into Thailand (this type of visa is valid for 15 days). However, it is best to check, in advance, as restrictions apply to some nationals.For more details please visit Ministry of Foreign Affairs web-site:
http://www.mfa.go.th/main/en/services/4908