Pyrochlore-free nano-sized (1-x)PMN-xPT (x=0, 0.10, 0.35) (PMN-PT) powders were synthesized from a mixture of the commercial oxides PbO, MgO, TiO 2 and Nb 2 O 5 by a high-energy ball milling process. The grain size estimated from XRD patterns for the three samples was about 10-30 nm. The high sinterability of the synthesized PMN and PMN-PT powders was evidenced by the fact that almost fully dense ceramics for the three systems could be readily achieved at temperatures as low as 950 o C. The relationship between microstructure, electrical properties of the PMN and PMN-PT ceramics and sintering temperature was investigated. The dielectric properties of 0.90PMN-0.10PT are comparable to those of the traditional ceramic samples, while 0.65PMN-0.35PT has a better higher dielectric constant than those of traditional ceramics after sintering at 1100 o C for 1 h.