During　past　more　than　30　years,　the　time-frequency　analysis　on　L2(ℝ)　such　as　wavelet　and　Gabor　analysis　has　been　extensively　studied,　but　the　time-frequency　analysis　on　L2(ℝ+)　has　not,　where　L2(ℝ+)　is　the　space　of　square　integrable　functions　on　the　half　real　line　ℝ+.　It　is　because　ℝ　is　a　group　under　addition,　while　ℝ+　is　not.　This　leads　to　L2(ℝ+)　admitting　no　nontrivial　shift-invariant　system.　The　present　article　gives　a　survey　on　the　time-frequency　analysis　on　L2(ℝ+).　It　only　focuses　main　ideas　instead　of　concrete　results.　Readers　may　refer　to　listed　references　for　details.　©　2022,　The　Author(s),　under　exclusive　license　to　Springer　Nature　Switzerland　AG.