Answer:
Mao's perhaps only positive legacy is that he was able to become victorious during the Chinese Civil War, and after that, unified the country under his rule. He also gave a sense of national identity and purpose to the Chinese nation after centuries of foreign power control and humilliation.
Mao's negative legacy could be summed up in two policies: the great leap forward, and the cultural revolution. This policies consisted in radical measures in order to adopt communism. They did not have the intended effects, and resulted in the deaths of a around one hundred million people.