Abstract: Experimental facility of Molten Fuel Coolant interactions（MFCI） was designed and set up in this paper.The falling course of molten melt drops was recorded by a high-speed camera and moving curves were obtained.Emphasis was placed on the effect of the drops temperature and the coolant temperature on the course of MFCI.Results showed that falling velocity of the metal drop decreased suddenly and rapidly at first then increased again after the metal drop impacting the surface of water.And then,falling velocity dropped slowly to a comparatively steady velocity.When coolant temperature was constant,falling velocity increased with the rising of drop temperature and when drop temperature was constant,falling velocity increased with the rising of coolant temperature.