Surface　texturing　is　one　of　the　effective　strategies　to　improve　bioactivity　of　implantable　materials.　In　this　study,　hierarchical　micro　and　nano　structure　(HMN)　were　fabricated　on　Co-Cr-Mo　alloy　substrate　by　a　movable　picosecond　laser　irradiation.　Respectively,　microgrooves　with　nano　ripples　and　islands　were　produced　on　Co-Cr-Mo　alloy　by　low　and　high　laser　power　density.　X-ray　diffraction　apparatus　(XRD)　phase　analysis　illustrated　that　substrate　was　in　the　phase　of　gamma-face-centered　cubic　structure(FCC)　before　laser　treatment,　while　it　was　in　epsilon-hexagonal　closest　packing　structure　(HCP)　phase　dominant　after　laser　treatment.　Cell　adhesion　and　proliferation　studies　showed　that　the　HMN　surface　exhibits　enhanced　adhesion　of　MC3TC-E1　osteoblast　and　promoted　cell　activity.　Analyzing　of　the　morphology　of　osteoblast　cells　indicated　cells　were　in　high　ratio　of　elongation　on　the　HMN　surface,　while　they　mainly　kept　in　round　shape　on　the　polished　surface.　Results　indicated　the　formation　of　hierarchical　structure　on　Co-Cr-Mo　alloy　was　able　to　improve　biological　performances,　suggesting　the　potential　application　in　cobalt　based　orthopedic　implants.　(C)　2017　Elsevier　B.V.　All　rights　reserved.