National Super Alliance leader Raila Odinga left the country for China on Saturday evening.
In a statement by his Communications Director Dennis Onyango, the purpose of the visit by the opposition leader was kept secret.
"Mr Odinga left Nairobi shortly after 5 pm today, October 13, 2018," read the statement.
Onyango termed the trip by Raila as a short visit as he is expected back in the country on Tuesday.
The former Prime Minister becomes the second high profile Kenyan to head to the Asian country after the recent visit by President Uhuru Kenyatta.
Raila had last visited China in 2012 while serving as the Prime Minister after reaching an agreement with the former President Mwai Kibaki following the disputed 2007 General Elections.
During the first visit, the opposition leader had gone to attend the Ministerial Conference of the Forum for China-Africa Cooperation.
The influential politician signed a number of deals with the Chinese leaders in order to boost trade between the two nations.
In August, Raila made a long week trip to Germany where he visited the Otto Von Guericke University Magdeburg after he received an invitation from his former colleagues.
During the trip at the university, the veteran politician met his former supervisor Prof. Adolf Neubauer and was later presented with a book on the history of the school.
The ODM leader at one point surprised his audience by speaking fluent German for 20 minutes.
It was revealed in July that Raila received a declaration from the government to be treated as a government representative in all his missions abroad.
