The Khitan people, who dominated a large part of Manchuria (an area mostly in Northeast China today). between 916 and 1125 AD, used two different scripts - the 'large script', which came into use in about 920 AD, and the 'small script', which was reputedly created in about 925 AD by the Khitan scholar Diela, who was inspired by the Uighur alphabet.
Although some parts of the scripts have been deciphered, there is no general agreement on the meaning of the majority of the scripts, which are examples of the writing systems for the now-extinct Khitan language, used in the 10th-12th century by the Khitan people who had created the Liao Empire in north-eastern China.
Source wikipedia
Sets of examples of the two variants, including logograms, syllabograms and possibly some phonograms, can be viewed here