Body weight and standard length traits are complex and important economic traits, and are also targets for selective animal breeding. Our objective was to identify QTL associated with body weight (BW) and standard length (SL) traits. We conducted a whole genome scan on 190 progeny from a full-sib family using 940 microsatellite markers. We conducted half-sib mapping using GridQTL software. We obtained 8 QTL distributed across 5 linkage groups (LG) during sire-based QTL analysis. For BW, 5 QTL were identified, of which 1 QTL occurred at the 95% genome-wide level, and was located at LG26. The remaining 4 QTL were at the 95% chromosome-wide level, explaining 12.5%–32.6% of phenotypic variance. For SL, 3 QTL overlapped with the BW QTL intervals. One QTL was identified at the 99% genome-wide level, and 2 QTL were at the 95% chromosome-wide level, explaining 18.4%–40.9% of phenotypic variance. During dam-based QTL analysis, we identified 11 QTL that were distributed across 7 LGs. Six QTL were associated with BW, of which one was at the 99% genome-wide level and was also located at LG26. Two QTL were identified at the 99% chromosome-wide level, leaving 3 QTL at the 95% chromosome-wide level, accounting for 15.7%–37.6% of phenotypic variance. For SL, 5 QTL were identified, of which 4 were the same marker or had a similar confidence interval with BW. Among these, 1 QTL was identified at the 99% genome-wide level, 1 QTL was at the 99% chromosome-wide level, and 3 QTL were at the 95% chromosome-wide level, explaining 16.7%–39.5% of phenotypic variance. Our results suggest that the most significant QTL maps to LG26 and is significant at the genome-wide level in both the sire and the dam-based analyses. The minimum confidence interval was only 3 cM, which can in mirror carp. Our results provide a useful reference for further candidate gene research and MAS in mirror carp.