Varying　degrees　of　strain　were　observed　in　L1(0)-Mn56Ga42　powders　via　low-energy　mechanical　cryomilling,　and　the　relationship　between　coercivity　and　strain　was　analyzed　in　detail.　With　increasing　milling　time,　the　powders　do　not　show　obvious　variations　in　grain　size　and　cell　parameters,　but　a　large　strain　is　induced　into　the　powders,　leading　to　a　remarkable　enhancement　in　coercivity.　A　maximum　coercivity　of　up　to　6.7　kOe　was　accomplished　for　20　h　milled　powders,　with　a　high　residual　strain　of　about　0.96%.　The　initial　magnetization　curve　indicates　that　the　coercivity　mechanism　is　mainly　governed　by　the　domain-wall　pinning　process　where　strain-induced　defects　act　as　pinning　centers.　Studies　on　heat　treatments　show　that　the　strain-induced　coercivity　contributes　to　over　50%　of　the　total　coercivity,　and　a　moderate　annealing　can　eliminate　the　strain,　changing　the　coercivity　mechanism　to　a　nucleation　process.