Abstract:We first present a vector of function basis BB(t)that satisfied BB(O)T=(0.0,1.0,0.0,0.0),BB(1)T=(0.0,0.0,1.0,0.0) BB′(O)T=(-0.5,0.0,0.5,0.0),BB′(1)T=(0.0,-0.5,0.0,0.5)BB"(O)T=(1.0,-2.0,1.0,0.0),BB"(1)T=(0.0,1.0,-2.0,1.0)Secondly we discuss the rational surface defined in tension-product form using above function vector BB (t). The interpolation surface implies the following results: (1)The surface interpolates control points; (2) It is second order parametrically continuous;(3) It is local and can be adjusted by weights. The effect of weights is also analysed and has similar result as bicubic rational B-spline surface.