Recent R&D of an edge Thomson scattering system for ITER (International Thermonuclear Experimental Reactor) are reviewed. We have designed a diagnostic laser system (5 J, 100 Hz) based on JT-60U diagnostic laser design (7.46J, 50Hz). New laser oscillator has been developed, and prototype amplifier has been assembled for ITER. Regarding a collection optics in a port plug, improvement of previous design has been carrying out. As for spectrometers, a new technique of Fourier transform spectrometer for Thomson scattering has been considered in addition to a filter polychromator.