Melt compounding technique was employed to prepare thermoplastic natural rubber (TPNR) nanocomposite. The ultrasonic bath was used to improve the filler-matrix interfacial adhesion. TPNR nanocomposites were prepared in the ratio of (70:20:10) from polypropylene (PP), natural rubber (NR) and liquid natural rubber (LNR) as a compatibilizer, with 4% NanolinDK4. The clay layers were found to be separated further with ultrasonic treatment as compared to the sample without ultrasonic treatment as exhibited from X-ray diffraction. Young's modulus, tensile strength and elongation at break of TPNR nanocomposites increased with ultrasonic treatment, the optimum results achieved at 3h. .The results obtained from dynamic mechanical analysis (DMA) curves indicate that the addition of MWNTs led to an increase in the storage modulus E' and loss modulus E'' with maximum value is obtained at 3 hours. The glass transition temperature (Tg) also increases with Ultrasonic treatment. Ultrasonic treatment can promote the dispersion of the clay in TPNR also improve the compatibility of organoclay filler and the TPNR matrix.