Two-dimensional natural convection in an inclined open cavity with bottom heated, two side insulated and the top open was investigated using PIV(Particle-Image-Velocimetry) measurement. Experimental results are presented for Prandtl number, Pr=6.62, cavity aspect ratio, A=1.0, Rayleigh number from $1.294{ imes}10^6;to;3.8841{ imes}10 ^6$, and inclination angles, ${alpha}=0$, 30 and 60 deg to the horizontal. It was found that the fluid rises along both side walls in the boundary layer region at ${alpha}=0;deg$, and the inclination of the cavity induced flow entrainment. The experimental results are in good agreement with the numerical results.