Theory of three cladding dispersion compensating fiber with negative dispersion slope was analyzed, and the effects of all parameters on the fiber′s characteristics were given. We found that the dispersion compensating fiber with negative dispersion slope can be achieved only in limited range and at the cost of larger negative dispersion value. And spinning preform when drawing was adopted to lower the polarization mode dispersion in fiber. The advanced dispersion compensating fiber was made through modifying chemical vapor deposition (MCVD) method.