This study investigated mineral element concentrations of acorns in Quercus acutissima and Quercus serrata seed orchard, so that to estimate the variation of these species based on the chemical composition in different clones from plus trees. The acorns were collected from ten clones of each species grown in the same clonal seed orchard. The nutritional concentration of acorns was significantly different between the clones and species. The concentration of nutrient for the whole acorn followed in this general sequence: P > K > Na > Mg > Ca > Mn > Fe > Zn > Cu . The mineral concentrations of acorns in clones of Q. acutissima and Q. serrata contained P (494 to 684 and 541 to 672 mg/100 g), K (114 to 569 and 140 to 251 mg/100 g), Na (57 to 121 and 49 to 85 mg/100 g), Mg (29 to 37 and 26 to 42 mg/100 g), Ca (10 to 53 and 26 to 68 mg/100 g), Mn (0.5 to 3.4 and 1.8 to 4.5 mg/100 g), Fe (0.7 to 1.1 and 0.0 to 2.2 mg/100 g), Zn (0.34 to 0.81 and 0.38 to 0.84 mg/100 g), and Cu (0.13 to 0.40 and 0.09 to 0.34 mg/100 g) respectively. Even though acorns of Q. serrata are smaller in size than Q. acutissima, acorns of Q. serrata contained significantly higher concentration of phosphorus, calcium, iron and manganese than Q. acutissima. Based on the mineral composition of the acorns, this study has shown that the clones of Q. acutissima and Q. serrata have different ability to accumulate mineral nutrients which could indicate the variation of Quercus species in terms of mineral acquisition and accumulation.