To improve the low quality of low-fat cheese, effects of λ-carrageenan on the physicochemical, structural and rheological characteristics of rennet milk gels made from milk of different fat contents (3.80%, 1.83% and 0.48%) were investigated. The results showed that with the addition of 0.03% λ-carrageenan, the moisture of all experimental samples was increased; the yield, protein and fat recoveries of the rennet gel made from the reduced-fat milk (1.83%) were significantly increased by 13.56%, 1.77% and 9.34%, respectively. In the low-field nuclear magnetic resonance ( LF—NMR) results, the T2 transverse relaxation time data demonstrated three distinct water populations. After the addition of λ-carrageenan, the adsorption water proportion was increased, but free water proportion was reduced. The gel time (G′=1Pa) of all the experimental groups was increased significantly after the addition of 0.03% λ-carrageenan （P<0.05), while the spontaneous whey precipitation was decreased （P<0.05). Meanwhile, the hardness, elasticity of milk gels were decreased significantly （P< 0.05). However, the addition of λ-carrageenan did not significantly affect the rheological characteristics of gel （P>0.05). Above all, there was no significant difference in the physicochemical and structural characteristics between the fullfat control and the reducedfat milk rennet gel (1.83%) after the addition of λ-carrageenan （P>0.05). In conclusion, the addition of λ-carrageenan could increase protein recovery rate of reducedfat gel while softening the texture simultaneously, which proved its great potential in improving the quality of low-fat cheese.