Five domestic kiwifruit varieties, Bidan (BD), Chiak (CA), Haegeum (HG), Haehyang (HH), and Mansoo (MS), in Korea and two imported varieties, Hayward (HW) and Hort16A (HT), from New Zealand were evaluated main active component groups in the fruit extracts involved in antioxidant and anti-dementia activities. HW, HT, and HH exhibited higher soluble solid content. BD, HG, and HH contained high total phenolics (TP), whereas two imported kiwifruits and green kiwifruits (MS and CA) had low TP content. BD showed the highest antioxidant and antidementia activities among kiwifruits studied. Vitamin C (Vc) in kiwifruit extracts had the highest correlation with antioxidant activities. TP in kiwifruits had the highest correlation with acetylcholinesterase inhibitory activity. Butyrylcholinesterase activity was not significantly correlated with TP or Vc content, but the butyrylcholinesterase activity was significantly correlated with total flavonoids. The results above suggest that domestic varieties have a potential source of Vc and phenolic bioactivities.