To solve the major drawback of the extended Gaussian image（EGI） for 3D model representation

we propose a multi-concentric extended Gaussian image with multi-resolution（MCEGI）.Firstly

the 3D model is normalized to the uniform canonical frame to obtain translation

scale and rotation invariance by the normal principal component analysis（NPCA） that we propose.Secondly

a 3D mesh model is decomposed into multi extended Gaussian spheres

and captures its surface area distribution with surface orientation in each Gaussian spherical grid.At last

this distribution function is transformed to spherical harmonic coefficients whose module is regarded as shape descriptors.The experimental results show that the performance of MCEGI on percesion-recall curve is better than REXT

and the dimension of its frature vector is only 26.5% of REXT’S dimersion.