The military aircraft came down in a wooded area of the northern province of Xiangkhouang, nearly 500km (311 miles) from the capital Vientiane.
The Laotian news agency and the Thai foreign ministry said the minister and his wife had died in the crash.
Up to 20 people were believed to be on board.
The Chinese state news agency Xinhua reports that they included the Laotian minister of public security, the secretariat of the Lao People's Revolutionary Party's central committee, the chairman of the propaganda training committee and the mayor of Vientiane.