Purpose To demonstrate the quantitative parameters derived from intravoxel incoherent motion imaging (IVIM) and diffusion kurtosis imaging (DKI) models can be used to improve the accuracy of MR imaging for differentiating among low- and high-grade pediatric brain tumors. Material and Methods This study was approved by the institutional review board. Forty-nine pediatric patients with histologically proved brain tumors who underwent IVIM and DKI were recruited in this study. All the MR exams were conducted on a 3T system (MAGNETOM Skyra, Siemens Healthcare, Erlangen, Germany). 13 b values ranging from 0-2000 s/mm2 were used the MR diffusion acquisition, The diffusion weighted images with b value of 0, 50, 100, 150, 200, 300, 400, 600, 800, 1000 s/mm2 were used to calculate IVIM parameters, and the diffusion weighted images with b value of 0, 700, 1400, 2000 s/mm2 were used to generate DKI parameters. The mean, minimum, and maximum value of IVIM [pure diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f)] and DKI [diffusion kurtosis (K) and diffusion coefficient (Dk)] parameters were measured. The IVIM and DKI values were measured in solid tumor regions, as well as in normal-appearing gray matter as a control. These values were compared between the low-and high-grade pediatric brain tumors by using the Mann-Whitney U test. Receiver-operating characteristic (ROC) analysis and logistic regression analysis were performed to evaluate the diagnostic performance of single-parametric and multiparametric models. Results None of the IVIM and DKI parameters exhibited significant differences in normal-appearing gray matter (P >.05). The Dk and D values were lower, whereas the K and fmin value was higher in high-grade pediatric brain tumors than those in low-grade pediatric brain tumors (all p <.05). The combination of DKmin and Kmax provided the largest area under the ROC curve (0.955) in the ROC analysis compared with individual parameters (Dmin, 0.891; DKmin,0.933; Kmax, 0.923 and fmin, 0.734), indicating an improved diagnostic performance for tumor grading. Conclusions The parameters derived from IVIM and DKI can be used to distinguish low-grade pediatric brain tumors from high-grade pediatric brain tumors. The combination of DKmin and Kmax value may serve as a noninvasive and quantitative imaging parameter for grading pediatric brain tumors in vivo.