Objective There are many disadvantages in prolonged immobilization aften the repair operation of Achilles tendon while with early functional exersice conspicuous result could be got in Achilles tendon repair. To probe into the mechanical characteristics of different suture materials and slip-knots in knotted condition and to provide reliable scientific evidences in support of the new technique uesd for suture combination without prolonged cast immobilization at postoperation in Achilles tendon rupture. Methods Measuring the mechanical properties of different suture materials by cutting 16 piescs of Coated Vicryl-910,Mersilk,Nylon,Polydioxanone filaments in the middle of the line respectively and tying 4 knots in each. Results The tests show that the maximum load?Young,s modulus?strength? Raroenergy are: PDS>Coated Vicryl>Nylon>Mersilk(P<0.05). Conclusion Despite PDS have the tendency of slip-knot, 1/0-PDS?1/0- Vicryl and 1/0 Nylon filament all have the admired strength for end to end simple repair. 5/0 PDS?5/0 Coated Vicryl filaments also have the significant strength and it would be better by tying more than 4 knots. Although Mersilk have less slip-knot instincts trend, it is not suitable for Achilles tendon repair. Nevertheless,The choosing of suture material is equal vital as choosing of the most advisable suture combination.