A study on the construction of weightwise perfectly balanced(WPB)functions has been conducted.A class of quartic function is given and its k-weight is analyzed.A new class of WPB functions is constructed by modifying the support of the class quadratic functions,and its weight-wise perfect balancedness and algebraic degree are proved.The k-weight nonlinearity of small-varia-ble WPB functions is calculated by computer program,and the results indicate that for the construc-ted new WPB functions,there are some improvements in certain weight k subsets compared with the existing functions.