The algebra of subquark charges is discussed in a subquark model in which leptons and quarks are made of an isospin-doublet spinor subquark “wakem” and a color-quartet scalar subquark “chrom”. The unitarity of the quark (or lepton) mixing matrix for the weak charged currents is shown to hold due to the SU(2) algebra of subquark isospin charges. It is also shown that the mixing matrix element decreases as fast as or faster than the inverse of quark (or lepton) mass difference. If isospin-color changing supersymmetric charges of subquark are included, the algebra is not closed. The energy-momentum operator can, however, be expressed as the supersymmetric charge squared as usual if there are twice as many chroms as wakems, which is the case. Possible symmetry-breaking and quantum number dependence of the lepton and quark mass spectra are conjectured.