This　paper　is　concentrated　on　the　nonclassical　properties　of　the　pair　coherent　states　during　the　interaction　with　a　three-level　Lambda-type　atom,　such　as　antibunching　effect,　violation　of　Cauchy-Schwarz　inequality　and　two-mode　squeezing.　Meanwhile,　we　find　these　nonclassical　properties　can　be　enhanced　in　the　case　that　the　atom　is　selectively　measured.