The zero point of charge (ZPC) and the remaining charge σp at ZPC are two important parameters characterizing surface charge of red soils. Fourteen red soil samples of different soil type and parent material were treated with dithionite-citrate- dicarbonate (DCB) and Na2CO3 respectively. ZPC and σp of the samples in three indifferent electrolytes (NaCl, Na2SO4, and NaH2PO4) were determined. Kaolinite was used as reference. The results showed that ZPC of red soils was affected by the composition of parent materials and clay minerals and in significantly positive correlation with the content of total iron oxide (Fet), free iron oxide (Fed), amorphous iron oxide (Feo), aluminum oxide (Alo) and clay, but it was negatively correlated with the content of total silica (Sit). The σp of red soils was also markedly influenced by mineral components. Organic components were also contributing factor to the value of σp. The surface charges of red soils were evidently affected by the constitution of the electrolyt The zero point of charge (ZPC) and the remaining charge σp at ZPC are two important parameters characterizing surface charge of red soils. Fourteen red soil samples of different soil type and parent material were treated with dithionite-citrate-dicarbonate (DCB) and Na2CO3 respectively. ZPC and σp of the samples in three indifferent electrolytes (NaCl, Na2SO4, and NaH2PO4) were determined. The results showed that ZPC of red soils was affected by the composition of parent materials and clay minerals and in significantly positive correlation with the content of total iron oxide (Fet), free iron oxide (Fed), amorphous iron oxide (Feo), aluminum oxide (Alo) and clay, but it was negatively correlated with the content of total silica . The σp of red soils was also markedly influenced by mineral components. Organic components were also contributing factor to the value of σp. The surface charges of red soils were evidently affected by the constitution of the electrolyt