Studies on the dynamic theological behaviors and electrical properties for multiwalled nanotubes filled high-density polyethylene composites were carried out．An obvious shear thinning phenomenon in η*vs ωwas found for composites of MWNTs content beyond 3％．A specific viscoelastic behavior．i．e．the so-called“second plateau”

appeared at low frequency region in cases of ψ>3％．This phenomenon could be regarded as a rbeological threshold

and could be attributed to the formation of some kind network structure due to MWNTs aggregation and the interaction between MWNTs and polymer matrix．A miulmum was found in the Iow ω region for the tanδ～ω curves．which also was believed to be induced by the formation of network structure．Results of dynamie frequcncv sweep after heat treatment of different time length and results of dynamic time sweep approved the previous postulation．Ultimately．the rheological threshold coincided with the electrical percoloation threshold which was found for the composites containing MWNTs of 2 wt％and 3 wt％．