  We investigate the dynamical process of optically trapped
X$^{1}$$\Sigma$$^{+}$ (v" = 0) state $^{85}$Rb$^{133}$Cs molecules distributing
in J" = 1 and J" = 3 rotational states. The considered molecules, formed from
short-range photoassociation of mixed cold atoms, are subsequently confined in
a crossed optical dipole trap. Based on a phenomenological rate equation, we
provide a detailed study of the dynamics of $^{85}$Rb$^{133}$Cs molecules
during the loading and holding processes. The inelastic collisions of
$^{85}$Rb$^{133}$Cs molecules in the X$^{1}$$\Sigma$$^{+}$ (v" = 0, J" = 1 and
J" = 3) states with ultracold $^{85}$Rb (or $^{133}$Cs) atoms are measured to
be 1.0 (2)$\times$10$^{-10}$ cm$^{3}$s$^{-1}$ (1.2 (3)$ \times$ 10$^{-10}$
cm$^{3}$s$^{-1}$). Our work provides a simple and generic procedure for
studying the dynamical process of trapped cold molecules in the singlet ground
states.
