A rapid and simple method for the determination of sialic acid (Neu5Ac) of yak milk fat globule membrane (MFGM) by HPLC with a diode array detector was developed and validated. Samples were cleaned up just by hydrolysis and derivatization before HPLC analysis. Separation was achieved with an Agilent TC-C18 column. The method showed a good linearity (r=0.997), the sensitivity results showed that the limits of detection and limits of quantification for sialic acid were 10.0 and 21.0 ${mu}g/mL$, respectively. The recovery of Neu5Ac was 95-97%. The method proved very simple and rapid for Neu5Ac analysis since separation was completely achieved at 12 min.