SSMS -> Right click database -> Properties -> Options -> Recovery Model. Yours is probably set to Full.

http://msdn.microsoft.com/en-us/library/ms189275(SQL.105).aspx">http://msdn.microsoft.com/en-us/library/ms189275(SQL.105).aspx

http://msdn.microsoft.com/en-us/library/ms189275(SQL.105).aspx