Dendrobium spp. were investigated for their chemical compositions with HPTLC/CMS, and biological properties, including antioxidant activities (DPPH and ABTS .+ assay), and anti-acetylcholinesterase (AChE). The ethanolic extracts of Dendrobium orchid pseudobulbs ( D. chrysotoxum ; DC, D. fimbriatum ; DF , D. lindleyi ; DL, and D. pulchellum ; DP) were found to contain caffeic acid, gallic acid, quercetin, rutin hydrate and vanillin. While luteolin was shown in D. fimbriatum and D. lindleyi extracts. D. lindleyi , and D. pulchellum extracts presented the high value of total phenolic and flavonoid contents, resulting in a strong antioxidant property. Moreover, D. chrysotoxum extract expressed AChE inhibitory potential. This research indicated that chemical compounds in Dendrobium would be involved with their biological properties, i.e. antioxidant and anti-AChE. This information can be used to support further in-depth research and product development in health, food, and pharmaceutical.