It is known that pure Co undergoes martensitic transformation from γ phase (fcc) to ε phase (hcp) by the movement of a/6<112> Shockley partial dislocations at around 400 ℃, however, there have been few systematic works on the SM effect in Co and Co-based alloys. In this study, the fcc/hcp martensitic transformation and the SM effect were investigated in Co-Al binary alloys(mole fraction of Al=0~16%).The γ/ε martensitic transformation temperatures were found from the DSC measurements to decrease with increasing Al content, while the transformation temperature hystereses were observed to increase from 60 ℃ at x(Al)=0 to 150 ℃ at x(Al)=16%. The SM effect evaluated by a conventional bending test was enhanced by the addition of Al over 4%(mole fraction) and Co-Al alloys containing over 10%(mole fraction) exhibit a good SM effect associated with the hcp → fcc reverse transformation above 200 ℃. The SM effect was significantly improved by precipitation of β (B2) phase and the maximal shape recovery strain of 2.2% was obtained, which can be explained by precipitation hardening. The crystallographic orientations between the β, ε and γ phases were also determined. Finally, the magnetic properties were investigated and it was found that the Curie temperature and saturation magnetization of Co-14% Al(mole fraction) are 690 ℃ and 120 emu/g, respectively. It is concluded that the Co-Al alloys hold promise as new high-temperature and ferromagnetic SM alloys. It is known that pure that undergoes martensitic transformation from γ phase (fcc) to ε phase (hcp) by the movement of a / 6 <112> Shockley partial dislocations at around 400 ° C. However, there have been few systematic works on the SM effect in Co and Co-based alloys. In this study, the fcc / hcp martensitic transformation and the SM effect were investigated in Co-Al binary alloys (mole fraction of Al = 0-16%). were found from the DSC measurements to decrease with increasing Al content, while the transformation temperature hysteresses were observed to increase from 60 ° C at x (Al) = 0 to 150 ° C at x (Al) = 16%. The SM effect evaluated by a conventional bending test was enhanced by the addition of more than 4% (mole fraction) and Co-Al alloys containing over 10% (mole fraction) exhibit a good SM effect associated with the hcp → fcc reverse transformation above 200 ° C. The SM effect was significantly improved by precipitation of β (B2) phase and the m The crystallographic orientations between the β, ε and γ phases were also determined. Finally, the magnetic properties were investigated and it was found that the curie temperature and saturation The magnetization of Co-14% Al (mole fractions) are 690 ° C and 120 emu / g, respectively. It is concluded that the Co-Al alloys hold promise as new high-temperature and ferromagnetic SM alloys.