Abstract: The wettability of polypropylene fiber was improved by DBD.Contact angles of polypropylene fibers were measured by a wetting balance and the adhesion power was calculated,and then the effect of treating power and time on the decay of wettability of polypropylene fiber was researched when using DBD treatment.The results indicate that any slight change of contact angle of the treated polypropylene fiber will bring about marked change of adhesion power decay of the fiber.The rate of decay of polypropylene fiber treated by DBD at different powers and durations of treatment exhibits very fast in the first 5 days and slows down and tends to equilibrium after 18 days.The decay of wettability of polypropylene fiber treated by DBD at power=200 W and time=0.31 s is slower and residual adhesion power is larger.