Structures and electronic properties are presented for three types of sp(2)/sp(3) mixed nano-carbon systems. Nano-diamond/nano-graphite conversion takes place around 1600degreesC, which changes the magnetism from sp(3)-defect-dominated one to pi-edge state originating one. Fluorination in the initial stage, which prefers edge carbon sites of nano-graphites, destroys the pi-edge states, and the succeeding fluorination generates sp(3)-defects with surrounding sigma-non-bonding state at the interior carbon sites. Diamond-like-carbon has non-equilibrium sp(2)/sp(3) mixed structure with atomic scale disorders, which is easily converted to 3D random network of nano-graphite domains by heat-treatment.