Background:　A　variety　of　embryonic　stem　cells　induction　and　differentiation　systems　have　been　established　so　far,　while　the　research　that　promotes　embryonic　stem　cells　to　differentiate　into　hematopoietic　stem　cells　is　still　at　an　initial　stage,　and　the　induction　efficiency　needs　to　be　improved.　Objective:　To　active　the　Wnt/β-catenin　signal　pathway　in　mouse　embryonic　stem　cells　with　exogenous　win3a　as　an　inducer,　and　then　to　observe　whether　the　activation　of　this　pathway　will　promote　the　directional　differentiation　of　embryonic　stem　cells　into　hematopoietic　progenitor　cells.　Methods:　The　ES-E14TG2a　mouse　stem　cells　were　cultured　with　the　exogenous　wnt3a　(100　μg/L)　for　21　days,　the　content　of　β-catenin　was　tested　by　cell　immunofluorescence　and　western　blot,　and　expression　of　Wnt　downstream　target　gene　was　detected　by　quantitative　reverse　transcription　PCR　to　determine　the　activation　of　Wnt/β-catenin　signal　pathway.　Single-layer　adherent　culture　method　was　used　to　induce　the　directional　differentiate　of　above-mentioned　cells　into　hematopoietic　stem　cells,　and　detection　of　hematopoietic　development　associated　surface　marker　CD34+　/Sca-1+　was　achieved　by　flow　cytometry;　meanwhile,　the　expression　of　hematopoietic　associated　gene　was　measured　by　quantitative　reverse　transcription　PCR.　Results　and　Conclusion:　We　found　that　β-catenin　accumulated　in　ES-E14TG2a　mouse　stem　cells　after　cultured　with　wnt3a　(100　μg/L)　for　21　days;　the　expressions　of　Wnt　downstream　target　genes　such　as　Pitx2,　Frizzled,　Sox17　and　Oct4　showed　the　different　degrees　in　increase,　meaning　the　activation　of　Wnt/β-catenin　signal　pathway.　Furthermore,　during　the　time　that　we　used　single-layer　adherent　culture　method　to　induce　hematopoietic　stem　cells,　the　CD34+/Sca-1+cells　accounted　for　20.2%　of　total　cells　at　day　14,　and　control　cells　only　accounted　for　11.9%.　Again,　expression　quantity　of　hematopoietic　associated　gene　BMP4,　FLK2　and　CD34　increased　while　Smad5　was　suppressed　significantly.　Our　data　suggest　that　sustaining　action　by　wnt3a　will　active　Wnt/β-catenin　signal　pathway,　and　also　promote　the　directional　differentiation　of　ES-E14TG2a　mouse　stem　cells　into　hematopoietic　progenitor　cells.