A bivariate rational biquartic interpolating spline based on function values with four parameters is constructed,and this spline is with biquartic numerator and biquadratic denominator.The interpolating function has a simple and explicit mathematical representation,which is convenient both in practical application and in theoretical study.The interpolating surface is C1 in the interpolating region when two of the parameters satisfiy a simple condition,when another two parameters are selected suitably,the interpolating function could be expressed in matrix form.The interpolating surface can be ...