We study the {gamma}-ray luminosity and beaming effect for Fermi blazars. Our results are as follows. (i) There are significant correlations between {gamma}-ray luminosity and radio core luminosity, and between {gamma}-ray luminosity and Rv, which suggests that the {gamma}-ray emissions have a strong beaming effect. (ii) Using the Lext/Mabs as an indicator of environment effects, we find that there is no significant correlation between {gamma}-ray luminosity and Lext/Mabs for all sources when we remove the effect of redshift. Flat spectrum radio quasars considered alone also do not show a significant correlation, but BL Lacertae objects (BL Lacs) still show a significant correlation when we remove the effect of redshift. These results suggest that the {gamma}-ray emission may be affected by the environment on a kiloparsec scale for BL Lacs.