The development of powerful computer algebra systems has considerably ex­ tended the scope of problems of scientific computing which can now be solved successfully with the aid of computers. However, as the field of applications of computer algebra in scientific computing becomes broader and more complex, there is a danger of separation between theory, systems, and applications. For this reason, we felt the need to bring together the researchers who now ap­ ply the tools of computer algebra for the solution of problems in scientific computing, in order to foster new and closer interactions. CASC''99 is the second conference devoted to applications of computer al­ gebra in scientific computing. The first conference in this sequence, CASC''98, was held 20-24 April 1998 in St. Petersburg, Russia. This volume contains revised versions of the papers submitted by the par­ ticipants and accepted by the program committee after a thorough reviewing process. The collection of papers included in the proceedings covers various topics of computer algebra methods, algorithms and software applied to scien­ tific computing: symbolic-numeric analysis and solving differential equations, efficient computations with polynomials, groups, matrices and other related objects, special purpose programming environments, application to physics, mechanics, optics and to other areas. In particular, a significant group of papers deals with applications of com­ puter algebra methods for the solution of current problems in group theory, which mostly arise in mathematical physics.