This book contains the refereed papers which were presented at the second In ternational Dortmund Meeting on Approximation Theory (IDoMAT 98) at Haus Bommerholz, the conference center of Dortmund University, during the week of February 23-27,1998. At this conference 52 researchers and specialists from Bul garia, China, France, Great Britain, Hungary, Israel, Italy, Roumania, South Africa and Germany participated and described new developments in the fields of uni variate and multivariate approximation theory. The papers cover topics such as radial basis functions, bivariate spline interpolation, multilevel interpolation, mul tivariate triangular Bernstein bases, Pade approximation, comonotone polynomial approximation, weighted and unweighted polynomial approximation, adaptive ap proximation, approximation operators of binomial type, quasi interpolants, gen eralized convexity and Peano kernel techniques. This research has applications in areas such as computer aided geometric design, as applied in engineering and medical technology (e. g. computerised tomography). Again this international conference was wholly organized by the Dortmund Lehrstuhl VIII for Approximation Theory. The organizers attached great impor tance to inviting not only well-known researchers but also young talented math ematicians. IDoMAT 98 gave an excellent opportunity for talks and discussions between researchers from different fields of Approximation Theory. In this way the conference was characterized by a warm and cordial atmosphere. The success of IDoMAT 98 was above all due to everyone of the participants."