Infliximab （IFX）， tumor necrosis factor-α inhibitor， is widely used in clinical practice for treating Crohn disease （CD）， but it is difficult to obtain the optimal therapeutic effect according to the conventional dose. It is recommended to perform therapeutic drug monitoring （TDM） for patients with poor therapeutic efficacy to guide clinical decisions. This paper reviews the pharmacokinetic characteristics of IFX， exposure-response relationship， the influencing factors of pharmacokinetic differences， and analytical methods in TDM. It is found that IFX doesn’t undergo liver or kidney metabolism， exhibits obvious exposure-response relationships in both the induction and maintenance phases of CD treatment； disease activity， albumin， antibodies to IFX （ATI） and other factors influence IFX’s exposure. It is recommended that trough concentration of IFX in the maintenance period should be kept above 3 μg/mL； the dose of IFX should be increased or medication interval should be shortened for patients with severe disease， low albumin levels and ATI formation， to promote therapeutic efficacy of IFX. It is suggested to use the same detection method for TDM of IFX in the same patient.