In order to have a compatible device in a sensor node in wireless sensor network, the sensors have to be made in micro-size, low cost, low power consumption and high performance. By using CMOS-MEMS technology, the micro sensors can be implemented with promising results.One of the central micro inertial sensors is an accelerometer which has the capability of sensing position change, vibration and shock of a device. A single-axis lateral capacitive accelerometer and a dual-axis in-plane capacitive accelerometer are made in this thesis. An alternative design of the single-axis accelerometer is discussed. The system designs are made through mathematical analysis in MatLab, 3D FEM simulation in CoventorWare and final layout in Cadence. The main issue is making compliant springs, large proof mass, considerable number of comb fingers, for fabricating micro sensors with high sensitivity and good noise performance. The single-axis lateral capacitive accelerometer has sensor sensitivity of 9.3mV/G, mechanical noise floor of 19uG/squareroot(Hz), linear measuring range of ±26G. The dual-axis in-plane capacitive accelerometer has sensor sensitivity of 9.3mV/G in one direction and 11.1mV/G in the cross direction.The chip is fabricated in a 0.25um BiCMOS process from STMicroelectronics. The post process is done at Carnegie Mellon University (CMU), USA and SINTEF MiNaLab, Norway.