  In this paper, we study the half-supersymmetric time-dependent configurations
in M-theory and their matrix models. We find a large class of 11D supergravity
solutions, which keeps sixteen supersymmetries. Furthermore, we investigate the
isometries of these configurations and show that in general these
configurations have no supernumerary supersymmetries. And also we define the
Matrix models in these backgrounds following Discrete Light-Cone Quantization
(DLCQ) prescription.
