The pipeline is expected to send 12 billion cubic meters of natural gas to Myanmar and southwest China annually. It will also reduce coal consumption by 30.72 million tonnes per year, said the China National Petroleum Corporation (CNPC).
The pipeline is 2,520-km long and 793 km of which is in Myanmar.
The gas pipeline will be linked with the pipeline that sends gas from China's northwest to the east coast where the industrial production is high.
Construction of the gas pipeline began in 2010.
A parallel crude oil pipeline between the two countries is being built. The crude oil pipeline is expected to go into operation by the end of 2013 and carry 22 million tonnes of oil per year.