Rice is a salt-sensitive plant， and soil salinization significantly impacts rice performance. Therefore， exploring excellent haplotypes of salt-tolerant genes and generating elite germplasm are of great significance for rice breeding. In this study， we firstly analyzed 236 core germplasm lines collected from the 3K Rice Genome Project Database， for salt tolerance during the seedling stage and throughout the entire growth period in the field. A highly salt-tolerant germplasm ‘71011’ from Australia was identified. This germplasm survived for 25.5 d and exhibited a salt tolerance level of 5.2 under 150 mmol/L NaCl treatment conditions， with a 100% survival rate under 0.3% to 0.5% salt treatment in the paddy field. We further conducted haplotype analysis on 20 reported salt tolerance genes in the core collection. Eight genes， including AKT1， CPK12， MYB48， P5CS1， SIK1， SKC1， SNAC1， and HKT1， were identified as having haplotypes associated with salt tolerance. One salt-tolerant variety ‘Yanfeng 47’ and one normal variety ‘Nongken 57’ were selected as parents to generate recombinant inbred lines. Finally， three molecular markers， which have been confirmed by PCR and qRT-PCR， were designed for selecting elite haplotypes of three genes， AKT1， MYB48， and HKT1. Through marker-assisted selection， we successfully developed three high salt-tolerance lines by aggregating these elite haplotypes. Our results provide available germplasm resources， molecular markers and innovative lines for breeding new salt-tolerant rice varieties.