title: Probing the physical properties and morphological evolution of transition protoplanetary disks authors: Jia-Wei Wang & Shih-Ping Lai abstract: Understanding how primordial circumstellar disks of young stellar objects dissipate gas and small dust grains and evolve into debris disks is crucial for advancing our knowledge in planet formation. Recent observations suggest that multiple pathways may exist for the disk evolution. In order to clearly identify the physical conditions influencing the evolutionary paths, here we perform a statistical analysis on two morphological parameters of the spectral energy distributions (SEDs), ƒÉturnoff and ƒ¿excess. ƒÉturnoff is the wavelength where the disk flux is equal to the stellar flux, and ƒ¿excess is the spectral slope at wavelengths longer than ƒÉturnoff. We compare ƒÉturnoff and ƒ¿excess of the theoretical SEDs from Robitaille et al. (2006) to those of the observational results from the Spitzer's c2d Legacy project, and discuss the possible evolutionary pathways for the transition disks.