Abstract: Maintenance of concrete structure has become a hot topic at present.In order to develop high performance materials for repair of concrete structure, two species of polymer latex were selected to modify cement mortar.Experiments of compressive strength, flexural strength, adhesive bending strength, absorption, and pore structure analysis were executed on polymer latex modified cement mortar.The test results in lab showed that with the additive of polymer latex, the adhesive bending strength between mortar and old concrete was enhanced, the water absorption coefficients of mortar decreased, and pore structure of mortar was improved.