HOHHOT -- Inner Mongolia autonomous region, the first province-level autonomous region established in China, celebrated its 70th birthday with a gala Monday.

More than 1,000 people dressed in traditional Mongolian costumes performed dances and Mongolian music on a square in Ulanhot city in the east of the region, where the regional autonomous government was founded on May 1, 1947.

Inner Mongolia covers an area of 1.18 million sq km, about 12 percent of the country's land area. The Mongolian population is 4.6 million, nearly one-fifth of the region's total.

Over the past 70 years, the region's economy has expanded from 537 million yuan ($78 million) to 1.86 trillion yuan ($270 billion), ranking first among the country's five autonomous regions. Its foreign trade volume increased from 11 million dollars to 11.7 billion dollars over the same period.