SAN FRANCISCO, June 24 (Xinhua) -- A photo exhibition in San Francisco, a city on the U.S. West Coast, kicked off Saturday morning a series of events to mark the 20th anniversary of Hong Kong's return to China.

The show displayed some five dozens of photos provided by China's Ministry of Foreign Affairs to feature historical moments, as well as social and economic life, of Hong Kong, since China resumed exercise of sovereignty over the territory on July 1, 1997.

The territory has been a special administration region, or SAR, under China's "one country, two systems" principle.

At a community center in Chinatown of San Francisco, where over 20 percent of residents are of Chinese descent, the highest percentage among major U.S. cities, more than 200 people, including Luo Linquan, Chinese Consul General to the city, and some Chinese language students, attended the opening of the event.

Co-organized by five local Chinese American community groups, plus some community leaders of various walks of life, the exhibition's opening was followed in the afternoon by volleyball competitions at a playground in the very center of Chinatown among 15 teams, and three top winners would be awarded at a ceremony in the evening.

To further celebrate the 20th anniversary of Hong Kong's return to China, a discussion forum is scheduled for Sunday, a dinner party for next Saturday and a performance gala next Sunday.