A new moored microstructure recorder(MMR) is designed, developed, tested, and evaluated. The MMR directly measures the high-frequency shear of velocity fl uctuations, with which we can estimate the dissipation rate of turbulent kinetic energy. We summarize and discuss methods for estimating the turbulent kinetic energy dissipation rate. Instrument body vibrations contaminate the shear signal in an ocean fi eld experiment, and a compensating correction successfully removes this contamination. In both tank test and ocean fi eld experiment, the dissipation rate measured with the MMR agreed well with that measured using other instruments.