Viscosity　and　density　have　been　measured　for　three　binary　mixtures　of　chlorinated　methanes,　that　is,　carbon　tetrachloride　+　chloroform,　carbon　tetrachloride　+　dichloromethane,　and　chloroform　+　dichloromethane,　and　for　one　ternary　mixture　of　1:1　mole　ratio　(carbon　tetrachloride　+　dichloromethane)　+　chloroform　at　303.15　K.　Molar　excess　volumes　V-E　and　viscosity　deviations　were　obtained　for　these　mixtures.　Molecular　interactions　have　been　interpreted　from　the　results.　There　are　very　weak　specific　interactions　between　CCl4　and　CH2Cl2　or　between　CCl4　and　CHCl3.　There　are　relatively　stronger　specific　interactions　between　CHCl3　and　CH2Cl2.　The　interactions　between　different　chlorinated　methanes　decrease　in　the　order　CH2Cl2　---　CHCl3　＞　CCl4　---　CH2O2　＞　CCl4　---　CHCl3.　The　interactions　are　considered　to　be　caused　mainly　by　the　differences　in　polarity,　size,　and　shape　between　different　component　molecules.