There is one Chinese character for the Kil surname. In the 1930 census, there was a significantly larger number of Kils living in Korea; it was the 62nd most common name in Korea. In a census taken after the Korean War, however, it had dropped to 72nd. The postwar census includes only South Korea, so it can be assumed that a relatively large number of Kils live in North Korea. There is only one Kil clan, Haep’yong. The origins of the surname are uncertain; it is believed to have originated in China. The surname Kil appears in Shilla period records, and so it is known to be old and well established.