Particle fragmentation and modification of crystallographic orientation in the aerosol-deposition process were investigated by molecular dynamics simulation. Atomistic models of bcc Fe and fcc Ni particles of 10 nm in diameter were subjected to collision to at substrates, and analyzed for their structural modification due to the impact. It was found that particle fragmentation takes place depending on both crystal structure and initial orientation of incident particles. Modification of crystallographic orientation were observed in both bcc and fcc particles and in bcc substrates. Microscopic mechanisms of particle fragmentation and orientation modification were found to be classified into three types, sliding, compression, and third phase generation, which are related to slip systems and relaxation of interface structures.