The government has said the attack, in the city of Kunming, was carried out by knife-wielding separatists from the far western region of Xinjiang, which is located on the borders of Central Asia.
The three men who were executed, Iskandar Ehet, Turgun Tohtunyaz and Hasayn Muhammad, were sentenced to death in September after being convicted of homicide and leading a terrorist organisation, the Kunming Intermediate People's Court said. A higher court later upheld the sentence, the official Xinhua news agency reported.
Police shot four other assailants dead during the knife attack, which injured 141 people on March 1, 2014.Xinjiang, home to the Muslim Uighur minority group, has been plagued by unrest in recent years. Some Uighurs have chafed under Chinese restrictions on their culture and religion.