Abstract: 　According to the principle of linear relationship between magnetic susceptibility and iron content in ore, the magnetic susceptilbility detector is used in Xishimen Iron Mine. The value of magnetic susceptibility of three types of ore samlpes, namely sample of powder ore, sample of ore model and sample ofdrill-holl model, are determinded. The interrelation between the value of magnetic susceptibility and threetypes of samples in Xishimen Iron Mine are given. The universal significance of ore grade determinationwith the magnetic susceptibility detector is pointed out.