Y 2 O 3 :Eu 3+ thin films have been grown on Si (100) substrates using Gd 2 O 3 :Eu 3+ as a buffer layer to reduce the lattice mismatch by pulsed laser deposition. The crystallinity, surface morphology and photoluminescence of the films are highly dependent on the thickness of buffer layer. The photoluminescence results obtained from Y 2 O 3 :Eu 3+ films grown on the Gd 2 O 3 :Eu 3+ buffer layer under optimized conditions have indicated that reducing lattice mismatch is very important factor for the growth of high quality Y 2 O 3 :Eu 3+ thin film phosphor. In particular, the incorporation of Gd 2 O 3 :Eu 3+ buffer layer induced an improved crystallinity, surface roughness and an increase of photoluminescence. The highest emission intensity was observed Y 2 O 3 :Eu 3+ films with 121nm Gd 2 O 3 :Eu 3+ buffer layer, whose brightness was a factor of 2.1 larger than that from Y 2 O 3 :Eu 3+ films without buffer layer.