Localization is a basic and critical requirement for wireless sensor network applications, e.g. target tracking, monitoring and intrusion detection. In the received signal strength (RSS) based localization method; the Cramer-Rao Lower Bound (CRLB) for the estimation precision can be calculated given the locations of beacons and parameters of signal propagation. We propose a sensor deployment scheme that optimizes the overall energy consumption of the sensor network with a pre-specified CRLB accuracy for a large scale RSS-based localization system.