The blaze started at around 2.30am on Friday (April 17) at Crossroad bar, a 70-year-old building made of wood and located in the city centre near Methi Hotel.
The fire spread quickly to four neighbouring buildings, including the house of the MP.
The fire engine sent by Mae Hong Son Municipality could not control the flames so they called for help from neighbouring sub-districts to bring more fire engines.
Governor Suwaphong Kitiphatphibun later visited the scene to check the situation. He said because the fire had started in the heart of the town, the damage was serious.
It was 4.20am before the fire was put out. Estimation of total damage and probe into the cause of the fire is underway.