The superior imaging manner of intravascular ultrasound becomes more and more widely used in the diagnosis of coronary heart disease and intervention therapy. However, as the frequency of ultrasound increases, strong speckled echo signal from blood may significantly decrease the contrast of lumen and arterial wall structure, which may make it difficult for doctor to diferentiate and measure geometrical parameters and physical parameters of lumen and plaque. In this paper a novel noise reduction method is introduced, which utilizes the temporal and spatial information of IUVS, that is blood echo speckles have higher temporal and spatial variation than the arterial wall. When signals transferred into the frequency field, tissue and blood present different frequency spectrum, then a radio of high frequency energy and low frequency energy is introduced to determine speckles or tissue. Result showed that the method can remarkably remove the speckle noise, increase the contrast and help doctor differentiate the arterial wall from the around tissues.