Abstract:The effects of heat shock on the cultural efficiency of stem cultures of carnation (Dianthus caryophyllus) were studied. The results showed that 43℃ 2h heat shock promoted or inhibited the differentiation of adventitious buds, and increased the induction percentage of calli derived from the stem explants of carnation. And also, heat shock obivously promoted the growth of calli on the subculture medium, but inhibited the growth of calli on the differentiation medium. Besides, heat shock increased the dry weight percentage of regenerated shoots and calli, too. We considered that the biological effects of heat shock had close relation to the exogenous conditions combined with heat shock, especially in exogenous phytohormone status.