The aim of this study was to investigate the effects of ratios of dietary non-fibrous carbohydrate to neutral detergent fiber(NFC/NDF) on the growth performance, nutrient digestibility and methane(CH4) production of Dorper×Thin-tailed Han crossbred ewes with 48.0-55 kg of body weight(BW). Thirty ewes with(48.0±0.5) kg BW were selected and divided into 3 treatments with 10 sheep in each treatment:NFC/NDF=0.78(concentrate/forage=35:65, ad libitum), NFC/NDF=1.03(concentrate/forage=50:50, feed restriction) and NFC/NDF=2.17(concentrate/forage=65:35, feed restriction). The trial lasted for 32 d, including a 17-d adaptation and a 15-d experimental period. The energy and crude protein intake were same in each treatment. The average daily weight gain of the treatment of NFC/NDF=0.78 was taken as the standard for the feed restriction of the treatment of NFC/NDF=1.03 and 2.17. The BW was measured before morning feed, and feed intake was recorded daily. The CH4 production, dietary energy and nutrient digestibility were determined during experimental period. The results showed that:1)The feed conversion efficiency in the NFC/NDF=2.17 treatment was significantly higher than that in the NFC/NDF=0.78 treatment(P<0.05), whereas no significant difference was observed between NFC/NDF=1.03 treatment and other two treatments(P >0.05). 2) The apparent digestibility of dry matter, organic matter, gross energy and metabolic rate of gross energy in NFC/NDF=2.17 treatment were the highest among the 3 treatments(P<0.05). The apparent digestibility of crude protein in NFC/NDF=2.17 treatment was higher than that in NFC/NDF=0.78 treatment(P<0.05), however, there was no significant difference between NFC/NDF=2.17 and NFC/NDF=1.03 treatments, or between NFC/NDF=0.78 and NFC/NDF=1.03 treatments(P>0.05). With the increase of ratio of dietary NFC/NDF, the apparent digestibility of NDF in NFC/NDF=2.17 treatment was the highest(P<0.05), whereas no significant difference was observed between NFC/NDF=0.78 and NFC/NDF=1.03 treatments(P>0.05). 3) The CH4 emissions in NFC/NDF=2.17 treatment was 32.53 L·d-1, which was significantly lower than that in NFC/NDF=0.78(58.03 L·d-1) and NFC/NDF=1.03(63.17 L·d-1) treatments(P<0.05), whereas no significant difference was observed between NFC/NDF=0.78 and NFC/NDF=1.03 treatments(P>0.05). The similar results were found in CH4 emission as a proportion of metabolic weight in the 3 treatments. With the increase of dietary NFC/NDF, the CH4 emission as a proportion of dry matter intake, organic matter intake and digestible organic matter intake in NFC/NDF=2.17 treatment was significantly lower than that in NFC/NDF=1.03 treatment(P<0.05), whereas no significant difference were observed between NFC/NDF=0.78 and other two treatments(P>0.05). The CH4 emission as a proportion of gross energy intake, digestible energy intake, metabolic energy intake had the similar results. The CH4 emission as a proportion of NDF intake and digestible NDF intake in NFC/NDF=1.03 treatment was significantly higher than that in the other two treatments(P<0.05), whereas no significant difference was observed between NFC/NDF=0.78 and NFC/NDF=2.17 treatments(P>0.05). The CH4 emission as a proportion of average daily gain and digestible ADF intake were similar among the 3 treatments(P>0.05). According to the production performance, nutrient digestibility, energy utilization and CH4 production, it will be recommended that NFC/NDF=2.17 under restriction feeding would achieve the best carbon-cutting results for Dorper×Thin-tailed Han crossbred ewes with 48-55 kg of BW.