  In this paper, we determine the connection coefficients for Okubo's canonical
solution matrix of types ${\rm I}$, ${\rm I}^*$, ${\rm II}$ and ${\rm III}$ in
Yokoyama's list.To solve these problems, we investigate a special type of Katz
operations for Okubo systems. These operations are used for explicit
constructing Okubo systems and their monodromy representations We construct
Okubo system and monodromy representations. We further apply their results to
the connection problem for canonical solution matrices.
