Highly sensitive photoinitiator takes an important role in the improvement of photo-polymerization for the advanced manufacturing of microsteric structures of the color filter. In the present work, we have investigated photosensitivity of a novel oxime ester photoinitiator with benzocarbazole as a chromophore in the polymerization process. By comparing the residual thickness of polymerized films in the color resists with those obtained by other oxime ester photoinitiators, it was found that the high absorption intensity at the i-line significantly increased the bottom-curing performance with good surface curing. Moreover, it was revealed that high quantum yield of this new photoinitiator also contributed to the increase in the high photosensitivity.