Abstract: To study the function of NtGGPPS4 in tobacco terpenoid synthesis, pHellsgate2-NtGGPPS4, an RNAi expression vector, was constructed and transferred by Agrobacterium-mediated transformation method. The transcript accumulation of NtGGPPS4 in transgenic tobacco plants was detected by qRT-PCR. α-and β-Cembrenediol and plastid pigments in transgenic tobacco plants were extracted by solvent extraction method. And the contents of α-and β-cembrenediol and plastid pigments were determined by GC-MS and LC-MS, respectively. The results showed that the expression level of NtGGPPS4 significantly decreased in transgenic tobacco plants. Comparing with the control, the contents of α-and β-cembrenediol and plastid pigments (neoxanthin, violaxanthin, β-carotene, chlorophyll a, chlorophyll b and lutein) significantly decreased. The results suggested that NtGGPPS4 was involved in the regulation of cembrenediol and plastid pigment biosynthesis in Nicotiana tabacum.