In this paper, bandgap characteristics of transversely probed hollow-core photonic crystal fibers (HC-PCFs) are numerically investigated by FDTD analysis. The transmission characteristic of the transverse trapping beam is described using concept of photonic partial bandgap. The field and intensity distribution are monitored at the central hollow-core for both TE and TM modes illuminated in the Γ-M direction. From the numerical results obtained, it is found that photonic stop bands are formed in the transmission spectrum. It is inferred that such partial bandgap studies are important for the application of HC-PCFs in the well-known area of optical tweezers where an efficient trapping can be performed inside the hollow-core.