The influence of substrate heat treatment on the crystallinity and surface morphology of Nd:YAG thin films on Si (111) substrate grown by femtosecond pulsed laser depostion was investigated. A mode-locked 300 mW fs Ti:Sapphire laser was used to grow the Nd:YAG on the Si (111) substrate. The substrate temperature was varied from 300°C to 600°C while keeping the same deposition pressure to 10-6 mbar for 180 minutes. Post deposition was performed from 400°C to 600°C for 180 minutes. The SEM reveals granular surface with different microstructural features depending on the growth parameters. The XRD patterns show preferential growth at (521) direction after post heat treatment. However, higher temperature results to degradation of crystalline qualities of the films.