Today little is known about the behavior of particles in solid-gas two-phase flow due to the lack of suitable measuring methods. In this paper, a new equipment based on optical fiber sensor technology is developed to measure the particle velocity and concentration. The measured results in a gas fluidized bed of 50 cm in four sides and 4.2 m in bed height are shown. This equipment consists of three main parts, the optical fiber sensor, the signal converter and amplifier and the data process system. The sensor is made of a bundle of fine optical fibers and is designed to measure the flow velocity, flow direction and the concentration, on the basis of the light correlation method for flow velocity and light scattering method for concentration. This equipment has 4 kinds of sample rates (1 MHz, 0.5 MHz, 0.25 MHz and 0.125 MHz) so the particle velocities from 0.5 to 25 m/s can be measured by use of different sample rates. The concentration ranges from 0.1 to 20 kg/m3. It has been confirmed that the measuring precision is about plus or minus 3% and plus or minus 5% for the flow velocity and concentration, respectively.