This study was conducted to examine dietary tea catechins (TC) supplementation on the fatty acid composition of muscle and ruminal bacteria in goats fed a maize stover-based diet. Forty goats, 8 months old (16.2 ± 1.2 kg), were randomly divided into four equal groups (10 animals in each group) and assigned to four experiment diets with TC supplementation at four levels (0, 2,000, 3,000 and 4,000 mg TC/kg feed, namely TC0, TC2000, TC3000 and TC4000, respectively). After a 60-day feeding period, all the goats were slaughtered and sampled. The results showed that dietary TC inclusion increased the average daily gain (ADG), protein content in the semimembranosus muscle and dry matter in the longissimus dorsi muscle (LD). Dietary TC supplementation increased the ratio of n-6 to n-3 fatty acid, the ratio of polyunsaturated fatty acids to saturated fatty acids was higher in TC3000 and TC4000 than in TC0 and TC2000 for LD. The current results implied that dietary inclusion of a suitable TC dose could improve the growth performance and increase the proportions of unsaturated fatty acids in muscle, and the biohydrogenation of ruminal microorganisms might change the profiles of fatty acids in the muscle of growing goats.