Quark mass matrices presented by a power series expansion in ||Vus||

In a general three-family Hermitian quark mass matrix model ({ital M}{sub {ital u}},{ital M}{sub {ital d}}), if we take a quark basis on which {ital M}{sub {ital u}} takes a diagonal form {ital D}{sub {ital u}}, the structure of {ital M}{sub {ital d}}{equivalent to}{ital {cflx M}} is almost determined by three down-quark masses ({ital m}{sub {ital d}},{ital m}{sub {ital s}},{ital m}{sub {ital b}}) and three Kobayashi-Maskawa matrix parameters ({vert bar}{ital V}{sub {ital u}{ital s}}{vert bar},{vert bar}{ital V}{sub {ital c}{ital b}}{vert bar},{vert bar}{ital V}{sub {ital u}{ital b}}{vert bar}), except for phases of the matrix elements {ital {cflx M}}{sub {ital i}{ital j}}. By using the experimental facts {vert bar}{ital V}{sub {ital u}{ital s}}{vert bar}{similar to}{lambda}, {vert bar}{ital V}{sub {ital c}{ital b}}{vert bar}{similar to}{lambda}{sup 2}, {vert bar}{ital V}{sub {ital u}{ital b}}{vert bar}{similar to}{lambda}{sup 3}, and {ital m}{sub {ital d}}/{ital m}{sub {ital s}}{similar to}{ital m}{sub {ital s}}/{ital m}{sub {ital b}}{similar to}{lambda}{sup 2}, the mass matrices ({ital D}{sub {ital u}},{ital {cflx M}}) are presented in terms of a power series in {lambda}.