MDHPLC is a new chromatographic technique, in which fractions from a separation system are selectively transferred to one or more secondary chromatographic systems with different separation mechanism to enhance resolution and sensitivity, or to decrease analysis times. In this review, the principle, characteristics and developments of MDHPLC are discussed. The various possible combinations of separation modes in HPLC [such as, size exclusion chromatography/reversed-phase chromatography (SEC/RPC), ion exchange chromatography/reversed-phase chromatography (IEC/RPC), normal bonded phase chromatography/reversed-phase chromatography (NPC/RPC), size exclusion chromatography/ion exchange chromatography (SEC/IEC), liquid-solid chromatography/reversed-phase chromatography (LSC/RPC), affinity chromatography/reversed-phase chromatography (AC/RPC) and achiral column/chiral column] and their applications are systematically reviewed with 63 references.