The present invention relates to a composition for promoting goblet cell proliferation or mucin secretion comprising thymosin beta-4, an isoform of thymosin beta-4, an analogue thereof, or a derivative of thymosin beta-4 as an active ingredient. The composition for promoting mucin secretion comprising thymosin beta-4, an isoform thereof or derivative thereof as an active ingredient according to the present invention promotes goblet cell proliferation and increases a mucin secretion amount. In particular, the composition for promoting mucin secretion increases the expression of Muc5AC, Muc1, Muc4, and Muc16. Therefore, the composition for promoting goblet cell proliferation or mucin secretion of the present invention is considered to have an excellent effect on goblet cell or mucin-related diseases.
