We firstly propose a novel flexible multi-rate passive optical network (PON) employing laddertype probabilistic shaping (PS) to enable adjustable and flexible multi-rate access without changing the modulation formats. We experimentally demonstrate a ladder-type PS PON with 64-ary carrierless amplitude and phase (CAP-64) modulation in an intensity-modulation and direct-detection (IM/DD) system over 25 km standard single-mode fiber (SSMF). The results verify that the proposed method can implement a rate flexible access even when the splitting ratio of power splitter changes dynamically. INDEX TERMS Ladder-type, probabilistic shaping, PON, flexible multi-rate access, CAP.