Many neuropsychiatric diseases are related to the abnormal development of brain tissue in infants. This study aims to analyze the changes in the parameters of magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) in brain development of infants aged from 2 months to 2 years old, and to explore the value of MRS combined with DTI in evaluating brain development of infants aged from 2 months to 2 years old. A total of 116 normal infants, who received whole brain MRS and DTI examinations after delivery in Children Hospital of Shanxi Province from September 2020 to May 2021, were selected and were divided into a group A (n=7, at the age of 2-6 months), a group B (n=28, at the age of 7-12 months), a group C (n=41, at the age of 13-18 months), and a group D (n=40, at the age of 19-24 months). After collecting the MRS and DTI data, statistical analysis was performed to compare DTI parameters and MRS metabolic products ratio. There were significant differences in the DTI parameters of frontal lobe, temporal lobe, occipital lobe, hind limb of internal capsule, fore limb of internal capsule, knee of corpus callosum, splenium of corpus callosum, and optic radiation among the 4 groups (P<0.05 or P<0.01). The values of fractional anisotropy (FA) showed an upward trend from the group A to the group D, while the values of apparent diffusion coefficient (ADC), axial diffusivity (AD), and radial diffusivity (RD) showed a downward trend, and the changes of parameters tended to slow down with age. In the left or right lentiform nucleus, the ratio of choline (Cho)/creatine (Cr) was decreased from the group A to the group D, and the group D was significantly lower than the group A and B (all P<0.01). The ratio of Cho/N-acetyl aspartate (NAA) was decreased from the group A to the group D, and the group D was significantly lower than the group A, B, and C (left lentiform nucleus, P<0.05 or P<0.01) or the group A, B (right lentiform nucleus, both P<0.01). The ratio of glutamine/glutamate (Glx)/Cr was decreased from the group A to the group D, and the group D was significantly lower than the group A, B and C (P<0.05 or P<0.01). The ratio of myo-inositol (mI)/Cr was increased from the group A to the group D, and the group D was significantly higher than the group A, B, and C (P<0.05 or P<0.01). The ratio of NAA/Cr was increased from the group A to the group D, and the group B, C, and D were significantly higher than the group A (P<0.05 or P<0.01). The ratios of mI/Cr and NAA/Cr in different brain regions from the group A to the group D showed an upward trend, and the ratios of Cho/Cr, Cho/NAA, and Glx/Cr showed a downward trend. The variation of each parameter tends to decrease with age. MRS and DTI can detect the brain development of infants aged from 2 months to 2 years old, and provide a basis for predicting brain diseases.