Problems　of　karst　collapse　may　often　occur　in　railway　and　highway　construction.　How　to　evaluate　the　influence　of　existed　karst　on　adjacent　tunnels　reasonably　is　meaningful　to　design　of　tunnel　engineering　in　karst　regions.　Considering　a　simplified　cave　as　ellipse　shape　section　and　tunnel　as　circular,　a　simplified　analysis　solution　for　stresses　and　deformation　characteristic　of　tunnel　due　to　the　influence　of　adjacent　ellipse　karst　cave　is　proposed　in　the　paper.　Schwarz＇s　alternating　method　was　used　to　derive　the　formulas　for　calculating　the　stress　and　displacement　of　the　surrounding　rocks.　Since　the　depth　is　larger　than　the　size　of　the　tunnel,　the　effect　of　gravity　gradient　is　ignored,　and　gravity　loads　are　simplified　as　uniform　normal　loads　along　far-field　boundary.　Comparison　between　the　results　from　the　closed　solutions　and　those　from　numerical　analysis　by　two-dimensional　finite　element　method　indicates　that　the　closed　solution　is　reliable　and　applicable　for　the　stress　and　displacement　field　around　circular　tunnels　adjacent　to　the　influence　of　an　ellipse　karst　cave　at　great　depth.