Enteral nutritional powder (VIVONEX) is mainly used to provide nourishment for critical patients and those patients who have just undergone surgical operation. Microelements included in it exert significant influence on the patients’ physical functioning. In the present paper, Enteral nutritional powder was digested with HNO3 by microwave digestion. After that, the content of eight metal elements in it, K, Na, Ca, Mg, Fe, Mn, Cu and Zn, was determined by FAAS. With the good linear correlations of standard curves (r=0.999 2～0.999 8), the recovery (n=6) ranging from 97% to 103%, and the RSD (n=6) from 0.46% to 1.12%, the method can be applied to simultaneous determination of several metal elements in enteral nutritional powder, and offers advantages of low detection limit, high sensitivity, speediness and accuracy. The determination of metal elements in samples by this method gives satisfactory results. Hence, the method helps to guarantee quality control of this kind of medicine, and supplies statistical evidence for the safety of clinical drug use.