A series of NaGdF₄:Er³⁺,Tm³⁺,Yb³⁺ upconversion luminescence phosphors with different Yb³⁺ ion concentrations were prepared by a hydrothermal method under 180℃ for 24h ,in which the molar ratio of NaF to rare earth ions is 5∶1.The structure and upconversion luminesce nce are characterized. The results of XRD indicate that all the samples are hexagonal phase NaGdF₄.Th e interplanar spacing of NaGdF_4phase is slightly affected by Yb³⁺ ions concentration.Under 980n m laser excitation,the upconversion luminescence spectra of samples show green emission from ²H11/2→⁴I15/2 and ⁴S3/2→⁴I15/2 transitions of Er³⁺ ions,red emis sions attributed to ⁴F9/2→⁴I15/2 transi tions of Er³⁺ ions,respectively,and blue emissions assigned to ¹G₄→³H₆ transitions of Tm³⁺ ions.The relative intensities of green to red emission and blue to red emission are governed by Yb³⁺ ions concentration in NaGdF₄:Er³⁺,Tm³⁺,Yb³⁺ phosphors,respectively.The possible upconversion luminescence mechanisms of th e samples are discussed. NaGdF₄:0.05%Er³⁺,0.3%Tm³⁺,50%Yb³⁺ phosphors exhibit bright white light under 980nm laser excitation,and the calculated CIE color coordinates are (0.342,=0.331).The white upconversion luminescence from NaGdF₄:Er³⁺,Tm³⁺,Yb³⁺ phosphors can be realized by adju sting the Yb³⁺ ions concentration.