One-dimensional metamaterials were realized by using composite right/left-handed transmission lines (CRLH TLs) , the transmission properties of the photonic crystals composed of metamaterials based on microstrlps lines were measured and analyzed. The experimental results indicate that the photonic crystals possess Bragg gaps and effective-single-negative (ESNG) gap, and the ESNG gap does not shift when the lattice constant varies by the same factor, and the edges of the gap are determined by zero average permittivity ε=0 and zero average permeabilityμ = 0, respectively. Zero-n gap and zero-φeff gap can be understood as an ESNG gap. The investigations of the photonic crystals consisting of metamaterials will benefit to the applications of the metamaterials in RF/microwave circuits and apparatus.