Improving the dynamics of the widely applied grid-connected power converters has been drawing a lot of interests in recent years. Since the currently installed grid-connected converters doesn't shown inertia effect in power processing, the lack of inertia in the electrical networks will become increasingly significant and less admissible when more and more renewable energy sources penetrate into the grid through grid-connected converters. An active power synchronizing controller for grid-connected power converters with configurable natural droop characteristics is proposed in this paper. The proposed controller is able to incorporate inertia, damping and configurable natural droop effect in the dynamics of the controlled converter. And in addition to the inertia characteristics, the droop and damping behaviors are discussed in detail. By a modified form of the swing equation of the synchronous generators, the droop behavior can be properly configured without undermining the damping characteristics. Experimental results are shown to validate the proposed controller.