We present results of an age and metallicity gradient analysis inferred from both optical and near-infrared surface photometry .
The analysis is based on a sample of 36 nearby early-type galaxies , obtained from the Early Data Release of the Sloan Digital Sky Survey and the Two Micron All Sky Survey .
Surface brightness profiles were derived in each band , and used to study the color gradients of the galaxies .
Using simple stellar population models with both optical and near infrared colors , we may interpret the color gradients in term of age and metallicity gradients of galaxies .
Using g _ { Z } \equiv d \log Z _ { met } / d \log R and g _ { A } = d \log { Age } / d \log R to represent the metallicity and age gradients , we found a median value of g _ { Z } = -0.25 \pm 0.03 
for the metallicity gradient , with a dispersion \sigma _ { g _ { Z } } = 0.19 \pm 0.02 .
The corresponding values for the age gradients were g _ { A } = 0.02 \pm 0.04 and \sigma _ { g _ { A } } = 0.25 \pm 0.03 .
These results are in good agreement with recent observational results , as well as with recent simulations that suggest both monolithic collapse and major mergers have played important roles in the formation of early-type galaxies .
Our results demonstrate the potential of using multi-waveband colors obtained from current and future optical and infrared surveys in constraining the age and metallicity gradients of early-type galaxies .