PROBLEM TO BE SOLVED: To provide a multi-point particle size distribution measuring system, capable of monitoring the particle sizes of a powder sample at a plurality of measuring points in a manufacturing process continuously and almost simultaneously. SOLUTION: The system for measuring multi-point particle size distribution consisting of a plurality of particle size sensors 1 respectively arranged in the vicinity of a plurality of measuring points A, B and C to measure the particle size distributions of the powder sample at the respective measuring points and a signal processor 30 for processing the measured data from the plurality of the particle size sensors to calculate the particle size distributions of the powder sample at the respective measuring points. Each of the particle size sensors is equipped with a laser beam source for irradiating the sample, which is introduced into a scattering field for measuring the sample, with laser beam, a photodetector consisting of a plurality of detection elements for detecting the intensities of the scattered beams of laser beam defracted and scattered by the sample introduced into the scattering field and a data transmission part for the sending out the measured data measured by the photodetector to the outside.
