The　energy　deposition　of　underwater　electrical　explosion　of　a　copper　wire　was　investigated　with　pulsed　voltage　in　the　time　scale　of　a　few　microseconds.　A　self-integrating　Rogowski　coil　and　a　voltage　divider　were　used　for　the　measurements　of　the　current　and　voltage　on　the　wire　load,　respectively.　Three　stages　of　melting,　liquid　state　and　vaporization　were　defined　by　the　definition　of　four　critical　time　points,　i.　e.　the　beginning　of　melting,　the　end　of　melting,　the　beginning　of　vaporization　and　the　beginning　of　breakdown.　The　deposited　energy　in　the　three　stages　and　before　breakdown　was　calculated　by　mathematical　method.　The　effects　of　circuit　parameters,　including　applied　voltage　and　circuit　inductance,　and　the　properties　of　copper　wire　consisting　of　the　length　and　diameter　on　deposited　energy　in　the　three　stages　and　before　breakdown　were　analyzed　by　experiment　and　calculation.　The　influence　of　circuit　parameters　and　properties　of　copper　wire　is　in　significant　in　the　melting　stage,　and　obvious　in　the　stages　of　liquid　state　and　vaporization.　By　adjusting　circuit　parameters,　the　deposited　energy　in　the　stage　of　liquid　state　and　before　breakdown　obviously　increases　with　the　increase　of　the　current　rise　rate.