A negative dispersion photonic crystal fiber (PCF) with dual core and composite lattice is proposed. The cladding is composed of two different air holes based on pure silica, and the inner core is formed with high effective index material doped with germanium. In order to realize negative dispersion, a ring of air holes in the cladding is removed. Using the finite difference frequency domain algorithm, the negative dispersion properties is analyzed. Results show that broadband negative dispersion with different levels can be achieved by optimizing air-hole pitch and two air-hole diameters. Broadband negative dispersion with full width at half maximum exceeding 200 nm is realized at 1.55 μm wavelength when the radius of the inner core, the air-hole pitch, the diameter of the larger hole and the diameter of the smaller hole is 0.95 μm, 2.15 μm, 1.9 μm, 1.1 μm respectively. To decrease the fabrication difficulty, air holes of more than 1 μm and hexagonal lattice are adopted. So this fiber can be used for broadband dispersion compensation in wavelength-division multiplexing optical fiber communication systems.