Dose　rate　effects　of　SiGe　heterojunction　bipolar　transistor　(HBT)　with　different　biases　were　studied.　A　three-dimensional　numerical　simulation　model　of　SiGe　HBT　was　established　with　Sentaurus　TCAD　software,　and　the　changes　of　Gummel　characteristics　and　transient　current　peaks　of　each　terminal　with　time　at　different　dose　rates　were　simulated.　The　results　show　that　transient　current　peaks　of　each　terminal　increase　with　dose　rate.　The　worst　biases　for　dose　rate　effect　were　different　for　different　terminals.　For　the　same　terminal,　the　transient　current　peak　is　different,　the　transient　current　of　collector　is　large　under　substrate　reverse　bias,　the　transient　current　of　base　is　large　under　cut-off　bias　and　transient　current　of　substrate　is　large　under　substrate　reverse　bias.　The　main　reason　for　the　phenomena　is　that　different　biases　affect　the　change　of　carrier　transport　mode　and　the　applied　electric　field.　©　2017,　Editorial　Board　of　Atomic　Energy　Science　and　Technology.　All　right　reserved.