This book constitutes the proceedings of the Third International Symposium on Unifying Theories of Programming (UTP 2010) held at East China Normal University, Shanghai, China, November15 16,2010inconjunctionwiththe12th International Conference on Formal Engineering Methods (ICFEM 2010). This symposium followed on the success of the ?rst one, held at Walworth Castle (Durham, UK) in 2006, and the second, held at Trinity College (Dublin, Ireland) in 2008. Based on the pioneering work of C.A.R. Hoare, He Jifeng, and others on unifying theories of programming, the aims of this symposium series...