To　investigate　the　cracking　sensitivity　of　cement　paste　under　the　restriction　of　steel　bars,　the　tensile　strength　of　the　cement　paste　with　different　mineral　admixtures　was　tested.　With　steel　bar　embedded　in　each　specimen　to　restrain　the　shrinkage　of　the　cement　paste,　continuous　strain　values　of　steel　bars　were　taken　down,　which　were　converted　into　the　stress　values　of　steel　bars.　Based　on　the　assumption　that　the　stress　value　of　the　steel　bars　equals　to　that　of　the　cement　paste　wrapping　around　the　steel　bars　within　a　certain　stress,　the　shrinkage　stress　of　the　cement　paste　and　its　tensile　strength　were　compared;　the　factors　affecting　the　cracking　sensitivity　of　cement　paste　were　analyzed.　The　results　show　that,　the　paste　cracking　sensitivity　will　decrease　with　water　to　binder　ratio　mW/mB　increasing　in　some　range;　when　the　mW/mB　is　same,　the　addition　of　fly　ash　also　decrease　the　cracking　sensitivity　significantly.　©,　2015,　Tongji　University.　All　right　reserved.