Abstract: 【Objective】This research is to construct the thiazole ring into the molecular skeleton of isolongifolanone for obtaining some new types of compounds with biological activity, developing the new application field and improving the utilization value of gum turpentine.【Method】Eleven novel isolongifolanyl thiazole derivatives(2a-2k)were synthesized by condensation and cyclization from isolongifolanone. Isolongifolanone was condensed with thiosemicarbazide to get the intermediate isolongifolanyl thiosemicarbazones, which was further cyclized with SymbolaA@-bromoacetophenone derivatives to obtain the compound 2a-2k. The structures of compound 2a-2k were characterized with FT-IR,¹H NMR, ¹³C NMR, and HPLC-MS. The antimicrobial and antitumor activities of 2a-2k were investigated with minimum inhibitory concentrations assay(MIC)and MTT assay, respectively.【Result】The antibacterial activities of 4-(4-chlorophenyl)-2-(2-(1,1,5,5-tetramethyltetrahydro-1H-2,4SymbolaA@-methanonaphthalen-8-(2H,5H,8αH)-ylidene)hydrazinyl)thiazole(2b)and 4-(naphthalen-2-yl)-2-(2-(1,1,5,5-tetramethyl-tetrahydro-1H-2,4SymbolaA@-methanonaphthalen-8(2H,5H,8αH)-ylidene)hydrazinyl)thiazole(2j)were better than that of others against Bacillus subtilis and Pseudomonas fluorescens, and their MIC were 7.5 μg/mL. The antibacterial activity of compound 2b was better than that of others against fungus, and its MIC values against Candida albicans and Candida tropicalis was 15.6 μg/mL. It was also found that the antitumor activities of isolongifolanyl thiosemicarbazide against HepG2 was the best than that of its cyclized derivatives, and its IC₅₀ was(34.5±0.8)μg/mL which was at the same level with that of the standard sample etoposide.【Conclusion】Isolongifolanyl thiosemicarbazide has the potential to be a new drug against HepG2 and deserves further research.