Never address people by their first names first|
Chinese people have first and last names like everyone else. However, in China, the last name always comes first. The family (and the collective in general) always takes precedence over the individual. Joe Smith in Minnesota is known as Smith Joe (or the equivalent) in Shanghai. If a man is introduced to you as Lî Míng, you can safely refer to him as Mr. Lî (not Mr. Míng).
Unlike people in the West, the Chinese don't feel very comfortable calling each other by their first names. Only family members and a few close friends ever refer to the man above, for example, as simply "Míng." They may, however, add the prefix lâo (laow; old) or xiâo (shyaow; young) before the family name to show familiarity and closeness. Lâo Lî (Old Lî) may refer to his younger friend as Xiâo Chén (Young Chén).