Silicon photonic crystal (PhC) nanocavity fabricated on a two-dimensional slab is attractive due to their small size and high-Q, which allow us to study optical nonlinearity at an extremely low input power. However, it has been fabricated by using electron-beam lithography, which makes it difficult to use this device for a practical use, due to the low fabrication throughput. Recently we showed that an ultrahigh-Q nanocavity is possible even when we use a photolithographic fabrication process that is widely used in silicon photonics by proper designing of the structure [1]. This study will open possibility for future mass production and the integration with other silicon photonics devices. In addition, there are other issues that needs to be studied, such as the re-configurability and achieving high coupling with optical fiber. We showed that by combining a tapered nanofiber and a PhC waveguide will allow us to achieve both high coupling and reconfigurable system, which will boost the functionality of the PhC nanocavity system. In this talk, I will review the progress on the high-Q photonic crystal nanocavities and discuss on the photolithographic fabrication and on the reconfigurable system achieved by combining the PhC waveguide with an optical tapered nanofiber.