Upon systemic administration, nanoparticles encounter serum proteins in the biological system resulting in the formation of "protein corona" on the surface. Increased understanding of the relationship between nanoparticles' "chemical identity" and "biological identity" can contribute to improved clinical translation. Recent studies of protein corona composition on nanoparticles, including from our group, suggest that a strategic choice of materials can influence the types of protein adsorbed from plasma and lead to improved delivery efficiency. This mini-review reflects on the fundamental knowledge of nanoparticle protein corona and highlights the recent applications of protein corona on nanoparticles' systemic circulation, cell, and tissue-specific delivery. Important considerations on the safety and efficacy aspects pertaining to the exploration of nanoparticle protein corona's targeting effect are also summarized. Finally, the future perspectives of protein corona research are discussed.