Pore　water　chemistry　can　exert　significant　controls　over　the　chemo-mechanical　behavior　of　chemically　active　soils,　which　has　not　been　characterized　by　using　the　traditional　Terzaghi＇s　effective　stress　to　a　satisfactory　extent.　In　this　paper,　based　on　the　concept　of　intergranular　stress,　a　generalized　effective　stress　for　saturated　active　soils　is　reconceptualized　and　incorporated　into　the　framework　of　the　modified　Cam-Clay　(MCC)　model　to　describe　the　mechanical　response　of　soils　upon　complex　chemical　and　mechanical　loadings.　The　proposed　model　is　capable　of　capturing　very　well　the　diverse　features　of　the　chemo-behavior　of　saturated　active　soils,　while　inheriting　all　the　advantages　of　the　MCC　model,　by　introducing　only　one　additional　parameter.　Within　this　context,　a　simple　equation　is　derived　to　predict　the　development　of　swelling　pressure　with　the　variation　of　pore　water　chemistry.　It　is　shown　that　the　proposed　swelling-pressure　equation　predicts　very　well　the　development　of　swelling　pressure　for　expansive　soils　with　a　dilute　pore　solution,　though　discrepancy　appears　at　high　concentration.　Because　the　double　layer　of　clay　particles　is　severely　suppressed　at　high　salt　concentration,　the　microfabric　of　soil　can　be　significantly　changed,　pointing　to　the　importance　of　taking　into　account　the　effect　of　soil　fabric　in　the　constitutive　modeling　of　active　soils　with　high　pore　water　concentration.