A　hidden　Markov　model　(HMM)　of　electrocardiogram　(ECG)　signal　is　presented　for　detection　of　myocardial　ischemia.　The　time　domain　signals　that　are　recorded　by　the　ECG　before　and　during　the　episode　of　local　ischemia　were　pre-processed　to　produce　input　sequences,　which　is　needed　for　the　model　training.　The　model　is　also　verified　by　test　data,　and　the　results　show　that　the　models　have　certain　function　for　the　detection　of　myocardial　ischemia.　The　algorithm　based　on　HMM　provides　a　possible　approach　for　the　timely,　rapid　and　automatic　diagnosis　of　myocardial　ischemia,　and　also　can　be　used　in　portable　medical　diagnostic　equipment　in　the　future.