[Objective] In this study, QTL mapping of cotton yield and fiber quality was conducted by using BC5S5 population of G.mustelinum L. importing line. It is expected that the excellent genes of G.mustelinum L. can be used for the improvement of Gossypium hirsutum L. through molecular breeding technology, which will lay a foundation for the study of yield and fiber quality of Gossypium hirsutum L.[Methods] In this study, the yield and fiber quality characters of BC5S5 population were determined and QTL was located. The yield characters were as follows: seed cotton weight per boll, lint weight per boll and lint percentage; The measured fiber quality characteristics were fiber length, fiber strength, micronaire value, maturity correction factor, fiber uniformity, short fiber content, fiber elongation and total water content. [Results] The results showed as follows: 1. Yield traits were obviously controlled by genes and less influenced by environment. Fiber quality traits were significantly influenced by the interaction between environment and gene, and were? more influenced by environment than genotype. 2. There was no significant correlation between yield traits and fiber quality traits. 3. A total of 80 QTLs were detected, including 63 QTLs related to fiber quality and 17 QTLs related to yield traits, distributed on 21 chromosomes. Among them, qLW-A06-1, qMCF-A12-1, qFS-A13-1, qSW-A10-1 and qSW-D06-1 were detected in multiple environments. 4. Four polymorphic loci A10:88383565, D06:36287101, D06:55819963 and D13:60179605 were identified, all of which were related to short fiber percentage (SFC). Eight QTL clusters were identified on ChrA01 (2), ChrA10 (2), ChrA13 (1), ChrD04 (1) and ChrD06 (2), which regulated multiple fiber quality and yield traits.