In general, standard benchmark suites are critically important for researchers to quantitatively evaluate their new ideas and algorithms. This paper presents CHStone, a suite of benchmark programs for C-based high-level synthesis. CHStone consists of a dozen of large, easy-to-use programs written in C, which are selected from various application domains. This paper also presents synthesis results which will be served as a baseline for researchers to compare their new techniques with. In addition, we present a case study on function-level transformation using a program in the CHStone suite.