PLD955 monofilaments were fabricated through melt extrusion followed by multiple hot extension process with a copolymer of 5%D-lactide and 95%L-lactide. PLLA monofilaments were prepared via the same process, and the diameter of monofilament is 0.16 mm. Accelerated degradation at 60°C and real time degradation at 37°C were carried out to study the degradation properties of PLLA and PLD955 monofilaments. At pre-determined time intervals, the mass changes, mol. weight, crystallization and tensile properties of the two monofilaments were monitored by mass measurement, GPC, DSC, XRD and tensile test. The results indicate that the mass retention of PLLA monofilament is stable both at 60°C for 21 d and at 37°C for 32 wk, but the mass loss of PLD955 is approx. 0.63% per wk. The half-life based on weight-average mol. weight of PLLA is about 10 times bigger than that of PLD955 at 37°C, while the half-life based on the break strength of PLLA is 10 times bigger than that of PLD955 at 60°C. It is proved that the addition of 5%D-LA could significantly shorten the degradation time of PLLA and be a promising method to adjust the degradation rate of PLLA to meet different degradation requirements of various medical devices.