The stability and stabilization are investigated for continuous-time linear time-invariant spatially interconnected systems composed of many subsystems with different dynamics and arbitrary and fixed connections. A computationally attractive necessary and sufficient condition is first derived for stability analysis of the systems, some necessary or sufficient conditions are then obtained, which essentially depend only on parameter matrices of each individual subsystem. Based on these stability conditions, a state feedback stabilizing controller is derived. These conditions avoid some algebraic computations such as inversion of high dimensional matrices, and utilize sufficiently the block-diagonal structure of system parameter matrices and the sparseness of the subsystem connection matrix. Numerical simulations show that they are computationally attractive in the analysis and synthesis of a large scale networked system.