The Premier League club's tour finishes in Kuala Lumpur on July 29th against a Malaysian Select XI.
Chelsea said in a statement: "The Macau game takes on an added significance because of the opposition. The city of Chengdu in the province of Sichuan was very seriously damaged by the recent Chinese earthquake. There will be a series of events around the game to raise awareness and money for the earthquake relief effort.
"Chengdu is also well known to Chelsea officials as it is one of the cities in the Vision China grass roots project which the club is a partner in with the Asian Football Confederation."
Chief executive Peter Kenyon said: "We are very happy to play this game in Macau as it has particular significance for us with our connections to Chengdu via the Vision China programme.
"We did look at playing a game in Chengdu, and now for very obvious and tragic reasons, that will not be possible. But we are delighted to assist in raising awareness for the earthquake relief effort as well as having excellent opposition to help prepare for the new season.
"We would like to thank our sponsors for the game, Windsor Arch, the Macau Sport Development Board and the Macau Football Association."