Quantum jump codes were introduced by Alber et al. (2001). Quantum jump codes have a close connection with combinatorial designs called t-SEED (t-spontaneaus emission error design). In this paper, we give a brief survey of quantum jump codes together with some new results. Firstly, fundamental properties of a t-error correcting quantum jump code are described. Secondly, a few examples of jump codes are given and an upper bound on the dimension of a jump code with a fixed length and given error correcting ability is derived. A relation between a t-SEED and a jump code is discussed and various constructions of t-SEEDs are given.