The absorption and velocity of ultrasound were studied for colloidal solution of gold (Au)-nanoparticles in polymer molecules refreshed reactive nascent surfaces of N- polyvinyl pyrrolidone (PVP) in an aqueous solution. The average size of Au-nanoparticles could be varied in 4-10 nm range by conducting the reaction at an elevated temperature 50-60ï°C. The frequency used were 5-25 MHz and 2 MHz for absorption and velocity at concentration range 0.5-1.0 wt% of Au-PVP samples in between 5-700C temperature. The results demonstrate that the primary reaction during the Au-nanoparticles-PVP colloidal formation occurs in divided groups in small micelles for the two lower concentrations 0.05 & 0.1 wt%. The results are analyzed for predicting the enhanced thermal conductivity of the samples and discussed in correlation with optical and electrical properties.