We demonstrated high-efficiency all-optical switching in an InGaAsP-InP photonic crystal resonator evanescently coupled with a microflber. The nonlinearity was based on carrier injection by single-photon absorption of 980-nm pump light. Carrier-induced and thermally induced shifts of resonance wavelengths were observed under continuous-wave pumping. In pulse operation, an instantaneous refractive index change of An Deltan ap 0.0035 and 1.5-nm blueshift of the resonant wavelength were achieved with pump energy of ~300 fJ, resulting in switching of the transmission output with 50% on-off contrast. This fiber-based configuration provides a quick and effective means for the study of optical nonlinearities in microcavities.