Radical 31 or radical enclosure (囗部) meaning 'enclosure' is one of the 31 Kangxi radicals (214 radicals total) composed of three strokes.

In the Kangxi Dictionary, there are 118 characters (out of 49,030) to be found under this radical.

囗 is also the 38th indexing component in the Table of Indexing Chinese Character Components predominantly adopted by Simplified Chinese dictionaries published in mainland China.