The magnetization of Hg_(0.89)Mn_(0.11) Te single crystal grown by vertical Bridgman method was studied by using superconducting quantum interference device magnetometer(SQUID Magnetometer). First, magnetization measurements were done under various magnetic fi eld strengths from-20 kOe to 20 kOe at 5 K, 15 K, and 77 K, respectively. Then, the magnetizations were measured with continuous changes of temperature in the range from 5 K to 300 K under the magnetic field of 0.1 kOe and 10 kOe, respectively. The modifi ed Brillouin function was well fitted with the data of magnetization vs. magnetic field strength. The analysis indicated that there was an antiferromagnetic exchange coupling among Mn~(2+ )ions. The results of reciprocal susceptibility vs. temperature fi t Curie-Weiss law very well at the temperatures above 40 K, but deviate from the law from 5 Kto 40 K, which shows that the antiferromagnetic exchange coupling among Mn~(2+) ions increases in the lower temperature range below 40 K. The experimental result was explained by extending higher-order terms in the calculation of susceptibility and fitted by a power law function. The measurements reveal that Hg_(0.89)Mn_(0.11) Te possesses paramagnetic properties at temperatures from 5 K to 300 K. The magnetization of Hg_ (0.89) Mn_ (0.11) Te single crystal grown by vertical Bridgman method was studied by using superconducting quantum interference device magnetometer (SQUID Magnetometer). First, magnetization measurements were done under various magnetic fi eld strengths from-20 kOe to 20 kOe at 5 K, 15 K, and 77 K, respectively. Then, the magnetizations were measured with continuous changes of temperature in the range from 5 K to 300 K under the magnetic field of 0.1 kOe and 10 kOe, respectively. The modifi The analysis of that there was an antiferromagnetic exchange coupling among Mn ~ (2+) ions. The results of reciprocal susceptibility vs. temperature fi t Curie-Weiss law very well at the temperatures above 40 K, but deviate from the law from 5 Kto 40 K, which shows that the antiferromagnetic exchange coupling among Mn ~ (2+) ions increases in the lower temperature range below 40 K. The experimental result was explained by extending higher-order terms in the calculation of susceptibility and fitted by a power law function. The measurements reveal that Hg_ (0.89) Mn - (0.11) Te possesses paramagnetic properties at temperatures from 5 K to 300 K .