<p style='text-indent:20px;'>Multilength variable-weight optical orthogonal codes(MLVWOOCs) are recently proposed for supporting multirate and integrated multimedia services in optical code division multiple access (OCDMA) networks. Some work had been done on MLVWOOCs with weight set <inline-formula><tex-math id="M1">\begin{document}$ W = \{3, 4\} $\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id="M2">\begin{document}$ \{3, 5\} $\end{document}</tex-math></inline-formula>. In this paper, we consider MLVWOOCs with <inline-formula><tex-math id="M3">\begin{document}$ W = \{4, 5\} $\end{document}</tex-math></inline-formula>, and some several infinite classes of optimal MLVWOOCs are obtained.</p>