Abstract: The size characteristics of the product after grinding of tungsten ore by high-pressure grinding roller from Yanglin'ao Dressing Plant of Hunan Yuanjing Tungsten Mine Industry and its relative grindability were studied. The results showed that: ① High pressure grinding roller can greatly increase the contents of intermediate and fine particle product; ②Pressure increasing at roller surface can improve the content of fine fraction and the crushing ratio; ③ Narrowing the closed-circuit sieve mesh size can increase the content of intermediate and fine products of high pressure grinding roller，and improve the relative grindability of closed-circuit roller grinding product. ④High pressure grinding roller can significantly improve the relative grindability of products. For coarse ores，its relative grindability was significantly increased; In case of the roll surface pressure of 4.5 MPa，mesh size of 3 mm，grinding fineness of -0.075 mm 50%，the relative grindability coefficient of the sample can reach 1.55，which increasing the first step grinding significantly.

Key words: High pressure grinding roller, Tungsten ore, Characteristics of particle, Screening size, Grindability