The reaction mechanism and the origins of regio- and enantioselectivities for Pd-catalyzed asymmetric arylation of aliphatic alpha-amino anion equivalents were investigated computationally. The results indicate that the reaction proceeds via mainly six sequential steps: deprotonation at alpha'-site of imine, coordination of alpha-amino anion to Pd-catalyst, oxidative addition, transmetalation, reductive elimination, as well as the final dissociation to release the product and regenerate the catalyst. The transmetalation is a key step on which both enantioselectivity and regioselectivity depend. The charge inversions of alpha- and alpha'-C atoms and the orbital interaction between Pd center and alpha-C in transmetalation step are responsible for the regioselectivity. Additionally, the intermediates before the dissociation step are critical in controlling the enantioselectivity. Noncovalent interactions analyses indicate that the enantioselectivity primarily arises from the CH center dot center dot center dot pi interactions of isopropyl (iPr) groups with the fluorene and the benzene rings for PdL1-catalyzed reaction.