In this manuscript we designed a circular photonic crystal fiber (PCF) having three rectangular holes filled with GaP in the core region, three air hole rings and one annular air ring in cladding region. We found highest negative dispersion for the 1.8µm pitch alongwith very low confinement loss at wavelength 1.55µm. This designed PCF offers high nonlinearity (39612 W-1km-1) and high negative dispersion (-6586 ps nm-1 km-1) alongwith zero confinement loss at 1.55µm wavelength. We also compared the proposed PCF with the previously published PCF structure and found that the nonlinearity and negative dispersion of the designed PCF are very high in comparison to circular air hole based PCF. Another performance parameters viz. birefringence, numerical aperture, effective area and effective material loss are also analyzed.