  A successful baryogenesis theory requires a baryon-minus-lepton number
violation if it works before the electroweak phase transition. The
baryon-minus-lepton number violation could also exist in some proton decay
modes. We propose a model to show that the cosmological baryon asymmetry and
the proton decay could have a common origin. Specifically, we introduce an
isotriplet and two isosinglet leptoquark scalars as well as two isotriplet
Higgs scalars to the canonical seesaw model. The decays of the Higgs triplets
can generate a desired baryon-minus-lepton asymmetry in the leptoquarks. After
the Higgs triplets pick up their seesaw-suppressed vacuum expectation values,
the leptoquarks with TeV-scale masses can mediate a testable proton decay.
