Protesting the move, China has launched a diplomatic protest, Australian Broadcasting Corporation reported.
The loggers were arrested in January this year during a crackdown on illegal forestry activities in northern Kachin state.
"Deal with this case in a lawful, reasonable and justified manner and return those people to China as soon as possible," Beijing's foreign ministry spokesman Lu Kang was quoted as saying.
Replying to him, Myanmar government refused to interfere in the judicial process.
"When our citizens break the law in other countries, [they] face sentence by those countries' laws. We cannot use diplomacy to intervene. I think China will understand," government spokesman Ye Htut said.
Life imprisonment in Myanmar is equivalent to 20 years, according to legal experts.