Because of the unique up-converting optical property, up-conversion luminescent materials NaYF4 : Yb, Er/Tm have a number of potential applications, including in solid-state lasers, three-dimensional displays, IR imaging, and many others. In resent years, up-converting NaYF4, : Yb, Er/Tm nanoparticles have attracted considerable interests due to their potential use as fluorescent labels for sensitive biological detection. The synthesis of up-converting NaYF4 : Yb, Er/Tm nanoparticles with high-quality and strong fluorescent performance is the precondition for their applications in biomedicine. In this paper, the studies on the synthesis, surface modification and biological applications of up-converting NaYF4 : Yb, Er/Tm nanoparticles are summarized with 60 cited papers for providing a beneficial reference to researchers in their further work.