Liu Kang was the son of a woman who came from the line of Great Kung Lao. He never knew who his father was, but Liu Kang grew up with his cousin Kung Lao who taught him the simple ways of shaolin skills. Liu Kang and his mother left for China, because the Wu Shi Academy din't accept Liu Kang.
They lived in US for years. But when Liu Kang was 15 he was visited by an ancient spirit who taught him the ways to to defeat the Shokan Prince Goro. Liu Kang joined the last Mortal Kombat tournament and defeated Goro.
But before the Grand tournament, he was attacked by Noob Saibot who made him lose his memory. Liu Kang eventualy got lost in Outworld, but then was taken by Kitana and became her enforcer. They fell in love with each other. Then they learn that Kitana was actually the daughter of the last Edenian King Jerrod and his queen Sindel. After that Liu Kang decides to help Kitana to regain her throne and restore Edenia.