We present new UBVIc CCD photometry of the young open clusters Trumpler 14 (Tr 14) and Trumpler 16 (Tr 16) in the {eta} Carina Nebula (NGC 3372). We also identify the optical counterpart of Chandra X-ray sources and Two Micron All Sky Survey point sources. The members of the clusters were selected from the proper-motion study, spectral types, reddening characteristics, and X-ray or near-IR excess emission. An abnormal reddening law R_V,cl_=4.4+/-0.2 was obtained for the stars in the {eta} Carina Nebula using the 141 early-type stars with high proper-motion membership probability (P_{mu}_>=70%). We determined the distance to each cluster and conclude that Tr 14 and Tr 16 have practically the same distance modulus of V_0_-M_V_=12.3+/-0.2mag (d=2.9+/-0.3kpc). The slope of the initial mass function was determined to be {Gamma}=-1.3+/-0.1 for Tr 14, {Gamma}=-1.3+/-0.1 for Tr 16, and {Gamma}=-1.4+/-0.1 for all members in the observed region for the stars with log m>=0.2. We also estimated the age of the clusters to be about 1-3Myr from the evolutionary stage of evolved stars and low-mass pre-main-sequence stars.