  We study the self-tuning of general brane junctions and brane networks on the
6-dimensional space-time. For the general brane junctions, there may exist one
fine-tuning among the brane tensions. For the brane networks, similar to the
5-dimensional self-tuning brane models, the brane tensions can be set
arbitrarily and there exists the singularity for the metric and bulk scalar.
And if we want to regularize the singularity, we will introduce the fine-tuning
among the brane tensions. In addition, because the 4-dimensional cosmological
constant we observe may be positive and very small, we discuss the brane
network with de Sitter brane intersections by introducing a bulk scalar.
