It　has　been　well　recognized　that　pore　fluid　salinity　significantly　affects　physical　and　mechanical　properties　of　clays.　However,　how　to　correlate　the　pore　fluid　salinity　effects　on　mechanical　behaviour　with　physicochemical　variations　induced　by　pore　fluid　salinity　changes　is　still　pending.　This　study　investigates　the　changes　in　liquid　limit,　oxide　compositions　and　compressibility　with　pore　fluid　salinity,　based　on　experimental　data　obtained　from　reconstituted　specimens　of　two　marine　clays　in　China.　It　is　found　that　oxide　compositions　vary　little　with　the　change　in　pore　fluid　salinity,　indicating　that　no　chemical　reaction　occurs　during　pore　salt　changing　for　the　investigated　clays.　Such　a　finding　means　that　the　pore　fluid　salinity　effects　on　compression　behaviour　of　reconstituted　clays　can　be　attributed　to　the　variations　in　physical　properties.　For　the　investigated　marine　clays　with　illite　as　predominant　clay　mineral,　the　void　ratio　at　liquid　limit　is　the　crucial　physical　index　of　assessing　the　pore　fluid　salinity　effects　on　the　compression　behaviour.　The　intrinsic　compression　concept　is　also　introduced　to　compare　the　compression　behaviour　of　reconstituted　clays　with　and　without　pore　salt.　A　quantitative　approach　is　proposed　to　assess　the　pore　fluid　salinity　effects　on　the　compression　behaviour　of　marine　clays　reconstituted　at　different　initial　water　contents.