1deoxyDxylose5phosphate synthase (DXS) is the first ratelimiting enzyme that controls the synthesis of plant terpenes in the methylDerythritol4phosphate (MEP) pathway. In this study, the sequence characteristics and bioinformatics of DfDXS gene of Dryopteris fragrans were analyzed, and its expression patterns under exogenous hormone, drought, salt stress, high and low temperature treatments were analyzed by qRTPCR technique, for exploring the role of DfDXS gene in terpenoid biosynthesis and stress resistance mechanism. The results showed that: (1) DfDXS1 fulllength 2 139bp encodes 712 amino acids, and DfDXS2 fulllength 2 160 bp encodes 719 amino acids. Domain analysis showed that it had a typical conservative domain of transketolase, including thiamine pyrophosphate binding site and transketolase domain. The genetic relationship is close to that of Selaginella moellendorffii DXS, Ginkgo biloba DXS1. (2) Under the treatment of salicylic acid (SA), the relative expression of DfDXS increased at first and then decreased; abscisic acid (ABA) inhibited the expression of DfDXS; DfDXS1 and DfDXS2 responded strongly to methyl jasmonate (MeJA) treatment, and the relative expression level of DfDXS1 was significantly higher than that of the control; Ethephon (Eth) inhibited the expression of DfDXS, but the expression of DfDXS1 was higher than that of the control at 3 h. (3) Polyethylene glycol (PEG), high temperature and low temperature all upregulated the expression of DfDXS1. The results showed that DXS gene plays a role in terpenoid synthesis and stress mechanism. This study provides a basis for further analysis of the molecular mechanism of stress resistance of D. fragrans.