Abstract: Infrared upconversion β-NaYF4 nanoparticles have attracted intensive research interest owing to their great potentials in biomedical applications as a kind of efficient host material. Recent advancements in the synthesis of upconversion β-NaYF4 nanoparticles can be categorized into thermal decomposition, hydrothermal reaction and ionic liquids-based synthesis. Additionally, the challenges of the synthesis and applications of infrared upconversion β-NaYF4 nanoparticles are discussed, as well as the developing trends.