In this paper, 66 rice (Oryza sativa L.) materials, including four upland rice, the backcross inbred lines (BILs) derived from the combination R974//R974/DXWR Dongxiang wild rice (Oryza rufipogon Griff., Hereafter DXWR) and their parents, were employed for evaluation of drought-resistance identification and screening of drought-resistance indexes of at seedling stage. Nine index traits were monitored correlating withfor assessment of drought resistance were monitored, those wereincluding maximum root length (MRL), number of root (NR), stem length (SL), dry root weight (DRW), fresh root weight (FRW), root relative water content (RRWC), leaf relative water content (LRWC), level for rolling leaf (LRL) and seedling survivability under repeat drought (SSRD), respectively. Comprehensive assessment of drought resistance based on the principal component analysis (PCA) indicated the line ‘1949’ showed the highest strongest drought resistance. Analysis on the stepwise regression equation and correlation demonstrated that MRL, RN, FRW, and RRWC significantly influenced the drought resistance, thus could be used as comprehensive index for identification of drought resistance at the seedling stage. Using the major gene plus polygene mixed inheritance model of quantitative traits, the inheritance genetic mechanism of drought-resistance at the seedling stage of in the BILs population at seedling stage was controlled by double two independent major genes and polygenes, based on comprehensive drought resistance value (CDRV). As a result, the DXWR could be precious natural resources for genetic improvement of drought resistance in cultivated rice.