Abstract: Microwave and ultrasonic wave techniques were used for disposing watermelon samples.The contents of Ca, Cu, Zn, Fe, K, Mn, Mg and Na in different parts of watermelon were determined by flame atomic absorption spectrometry.The recoveries for each element were within the range of 95% to 105%, the average recoveries were 96.2% to 104.0%, and RSD of the method for 10 times determinations were 0.23% to 2.98%, the method was accuracy and precise.The results showed that the contents of potassium, calcium and magnesium were high in rind, endodermis, pulp and dried seed.The order of the content of Ca was rind>seed>endodermis>pulp, Cu was seed>rind>endodermis>pulp, Zn was seed>rind>pulp≥endodermis, Fe was seed>rind>pulp>endodermis, K was seed>endodermis>rind>pulp, Mn was seed>rind>pulp>endodermis, Mg was seed>rind>endodermis>pulp, Na was seed>rind>endodermis>pulp.The results of watermelon could provide theoretical basis for developing and utilizing the melon.