Abstract: Using 14C tracer technique, the effect of cotton ( Gossypium hirsutum L. ) seedling transplantation on the 14C assimilates and 14CO2 assimilate distribution as well as redistribution were studied. It was shown that transplantation of seedlings increased both 14C assimilates and their retmnslocation in cotton seedling markedly. The distribution of 14C assimilates in the plant organs 3 days after labelling indicated that transplantation could increase the translocation of 14C assimilates into the roots and main stem, but decrease it into the tip of cotton seedling, which benefited in establishing good quality of the seedling. Furthermore, the apportionment of 14C assimilates into growing points decreased, in favor of avoiding or reducing spindling of stead growth and improving the developement of florat buds. From bloom to boll great increase of the apportionment of 14C assimilates into bolls of the transplanted plant could promote the growth and the development of squares and bolls.

Key words: Gossypium hirsutum, Transplanting, 14C assimilates, Distribution, Redistribution