This research aims at analyzing aspects determining supporting industries (SIs) to serve the task of planning and developing such industries. Analyses show that Vietnamese SIs are very small and unable to help the manufacturing sector increase its added value and join the global value chain. The results find the following culprits: the plan and policies on SI development are not compatible with main trends of market specialization and global value chain; chain of domestic industrial production is till lacking; and inter-industry cooperation is poor. Policy recommendations, therefore, are as follows: establishing the exact list of SIs that help increase the added value of local industrial production and integrate into the global value chain; and planning space, time, track, and methods needed for carrying out such policies. Besides the development plan, the paper also offers suggestions about policies to promote SIs, such as legal infrastructure for SI development, design of a value chain for SIs, building of clusters of SIs, and mechanism for promoting SI development.