Abstract: Packet-based transmission of data over a network with limited bandwidth would result in lost data. The H2 output feedback control problem for a class of networked control system with both measurement data and control data missing simultaneously is considered in this paper. The packet loss is modeled as a Bernoulli distributed white sequence with a known conditional probability distribution. A sufficient condition for the existence of a dynamic output feedback controller is present via matrix inequalities, such that the closed-loop system is exponentially mean-square stable and a prescribed H2 performance is guaranteed. The sequentially linear programming matrix method (SLPMM) is used to solve the matrix inequalities. Numerical example is provided to demonstrate the feasibility of the proposed condition and the controller design procedure.