Abstract: In order to investigate the correlation between respiratory rate and muscle quality in fresh rainbow trout, the changes of muscle quality corresponding to different respiratory rates were analyzed. The contents of lactic acid, glycogen, malondialdehyde (MDA), nucleotide compounds and pressurized water loss rate were measured. The result showed that with the increase of respiratory rate, the content of glycogen decreased, the content of malondialdehyde and nucleotide compounds, the rate of pressure water loss increased. When the respiratory rate increased from 83 to 95 times/min, the lactic acid content increased significantly from 1.46 to 2.37 mmol/g prot (P<0.01). Pearson correlation analysis showed that respiratory rate of fresh rainbow trout was very significantly correlated with lactic acid content, MDA value and pressurized water loss rate (P<0.01), and significantly correlated with muscle quality such as glycogen content, AMP content, IMP content and total Hx and HxR content (P<0.05). The correlation coefficients were 0.987, 0.951, 0.939, -0.897, 0.847, 0.896, 0.882, respectively. This study indicated that there was a strong correlation between respiratory rate and muscle quality, and the muscle quality of fresh rainbow trout (Oncorhynchus mykiss) could be preliminarily predicted by monitoring respiratory rate.