A　series　of　one-dimensional　incremental　load　consolidation-hydraulic　conductivity　tests　was　performed　on　reconstituted　clays.　Based　on　these　tests,　together　with　the　test　data　compiled　from　the　literature,　the　quantitative　interrelation　between　the　variation　of　hydraulic　conductivity　in　the　vertical　direction　with　void　ratio　and　the　compression　behaviour　is　established.　It　is　found　that　the　hydraulic　conductivity　in　the　vertical　direction　can　be　expressed　as　a　function　of　void　index,　initial　void　ratio　and　void　ratio　at　the　liquid　limit.　The　effects　of　initial　void　ratio　and　void　index　on　hydraulic　conductivity　in　the　vertical　direction　for　a　given　clay　with　a　given　void　ratio　at　the　liquid　limit　can　be　comprehensively　attributed　to　the　effect　of　void　ratio　on　hydraulic　conductivity　in　the　vertical　direction.　These　two　findings　introduce　the　point　that　the　hydraulic　conductivity　in　the　vertical　direction　is　a　function　of　void　ratio　and　void　ratio　at　the　liquid　limit.　Empirical　equations　are　proposed　to　determine　the　hydraulic　conductivity　in　the　vertical　direction　using　void　ratio　and　void　ratio　at　the　liquid　limit　or　using　effective　vertical　stress,　initial　void　ratio　and　void　ratio　at　the　liquid　limit.　These　two　empirical　equations　are　correlated　based　on　the　concept　of　intrinsic　compression.