We have analyzed data from the FSRQ PKS 1510-089 collected over a period of eight years from August 2008 to Dec 2016 with the Fermi-LAT. We have identified several flares of this highly variable source, studied their temporal and spectral properties in detail, and compared with previous works on flares of PKS 1510-089. Five major flares and a few sub-flares or sub-structures have been identified in our study.
The fastest variability time is found to be 1.30$\pm$0.18 hr, where we estimate the minimum size of the emission region to be 4.85$\times$10$^{15}$ cm. In most of the flares, the $\gamma$-ray SEDs are better fitted with a log-parabolic distribution compared to a simple power law or a power law with exponential cutoffs. This has strong physics implications regarding the nature of the high-energy $\gamma$-ray emission region.