Chinese Premier Li Keqiang also sent a message to his Sri Lankan counterpart Ranil Wickremesinghe to express his congratulations, Xinhua reported.
In his message, Xi said China and Sri Lanka are traditionally friendly neighbours, and relations between the two countries have remained unshakable and become even firmer as time goes by.
Recalling his successful state visit to Sri Lanka in September 2014, Xi said he was deeply touched by the Sri Lankan people's profound sentiments and friendship towards the Chinese people.
China attaches great importance to its ties with Sri Lanka and stands ready to work with the South Asian country to promote development of a strategic cooperative partnership between the two, said the Chinese president.
The Chinese premier in his congratulatory message said that since the establishment of diplomatic relations between China and Sri Lanka in 1957, bilateral ties have always undergone healthy and stable development, turning out to be a paradigm for friendly coexistence and mutually beneficial cooperation between the two countries.
The Chinese side is ready to work with Sri Lanka in deepening the traditional friendship and expanding pragmatic cooperation, he said.