Abstract: Barium titanate particles were hydroxyl and mercapto functionalized，and nano-sized Ag particles successfully grafted onto the surface of barium titanate to prepare xAg@BT（x is the mass fraction of Ag and BT is barium titanate） parti- cles，and Ag@BT/PVDF and BT/PVDF nano composite materials were finally prepared by solution blending method.Results showed that，xAg@BT nano-sized particles had a core-strawberry structure，Ag particles with the size of 2~16 nm was success- fully decorated on the surface of barium titanate particles；dielectric loss and electrical conductivity of the composite were de- creased at low frequency as the introduction of nano-sized Ag particles，and when the mass fraction of Ag nano-sized particles was 1.0%，the composite′s characteristics breakdown strength reached the maximum value.Compared with the traditional composite material nano BT/PVDF，1%Ag@BT/PVDF composite had more excellent electrical properties.

Key words: barium titanate；composite materials；Ag, dielectric properties