Department of Physics, Rikkyo University, Tokyo Japan

Yohkoh observed a few gamma-ray flares in November 1997 to December 1998 and temporal dependence of gamma-ray emission was studied. The main results obtained from the Yohkoh observations are (1) Temporal variation in a ratio of Low-FIP to High FIP line fluxes, (2) Evolution of accelerated proton spectrum, (3) Ratio of bremsstrahlung to nuclear line fluxes, (4) Energetics of accelerated protons and electrons, (5) Photospheric ³He to H abundance ratio and (5) Positron annihilation line. We discuss the accelerated particle spectra and elemental abundances at the gamma-ray production site.