Abstract: The deposition of particle-like corrosion products on the surface of heat transfer tube in the primary circuit has negative effects on safety operation and radiation protection of the system. An experimental system was adopted to study deposition mechanism of particle-like corrosion products in the primary circuit of PWR. The deposition distribution of particle-like corrosion product Fe₃O₄ in heat transfer tube was studied. The effects of tube radius, pH value and particle radius on deposition were compared. Through the experiment, the rules of deposition distribution in tube were founded. The ranges of pH value and particle radius for maximum deposition rate were given, which can be applied as a reference for PWR chemical controls.