  We present a systematic analysis on coherent states of composite bosons
consisting of two distinguishable particles. By defining an effective composite
boson (coboson) annihilation operator, we derive its eigenstate and commutator.
Depending on the elementary particles comprising the composite particles, we
gauge the resemblance between this eigenstate and traditional coherent states
through typical measures of nonclassicality, such as quadrature variances and
Mandel's Q parameter. Furthermore, we show that the eigenstate of the coboson
annihilation operator is useful in estimating the maximum eigenvalue of the
coboson number operator.
