It　is　often　recognized　that　organic　matter　contained　in　natural　clays　and　dredged　clays　is　detriment　to　the　engineering　properties　by　increasing　their　compressibility.　This　study　takes　humic　acid　as　an　example　to　illustrate　that　organic　matter　may　decrease　the　compressibility　of　reconstituted　clays　with　a　wide　spectrum　of　predominant　clay　minerals:　kaolinite,　illite　and　smectite,　based　on　experimental　results　from　thirty　types　of　one　dimensional　incremental　load　consolidation　tests.　It　is　found　that　the　main　factors　of　influencing　the　compression　behaviour　of　reconstituted　clays　with　humic　acid　are　initial　void　ratio　and　void　ratio　at　liquid　limit.　The　difference　in　compression　curves　between　reconstituted　clays　with　and　without　humic　acid　can　be　attributed　to　humic　acid　effects　on　particle　density　and　liquid　limit　of　clays.　The　humic　acid　effect　on　the　compressibility　of　smectite-dominant　reconstituted　clays　is　found　to　be　much　more　sensitive　than　that　for　kaolinite-and　illitedominant　reconstituted　clays.　A　quantitative　approach　is　also　suggested　to　assess　the　compression　behaviour　of　kaolinite-　and　illite-dominant　reconstituted　clays　with　humic　acid　using　intrinsic　compression　concept.