【Abstract】Objective To investigate the safety and efficiency of the second generation of LMWH Clivarin in chronic hemodialysis. Methods A cross covered trial was made, patients were given Clivarin and Fraxiparine in 4 times HD in different orders. Results The rate of Xa activity of Clivarin group dropped more than Fraxiparine group and APPT was shorter in Clivarin group than that in Fraxiparine group. There were no differences of the decrease of effective urea clearances in the two groups. Conclusion Clivarin provides a more effective anti-Xa activity and a small bleeding risk than Fraxiparine in CHD patients.