This book constitutes the refereed proceedings of the 4th Annual International Computing and Combinatorics Conference, COCOON'98, held in Taipei, Taiwan, in August 1998. The 36 revised full papers presented were carefully reviewed and selected from a total of 69 submissions. The book is divided in topical sections on computational geometry; algorithms and data structures; computational complexity; parallel and distributed processing, and switching networks; graph theory; and combinatorics and cryptology.