Purpose <p>To explore the effect of the choroid plexus volume (CPV) changes on paravascular drainage function, Alzheimer’s disease (AD) pathology, and the kidney-brain axis in AD.</p> Methods <p>A total of 74 AD patients and 32 healthy controls (HC) were included for this study, and cerebrospinal fluid (CSF) AD biomarker data and serum creatinine levels were collected from 28 AD patients. CP volume (CPV) calculation was performed using 3D-T1 images and the diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) index was calculated using DTI images to assess paravascular drainage function. Mediation analyses were used to assess the mediating role of CPV and ALPS index between kidney function and AD pathology.</p> Results <p>AD patients had larger CPV and smaller ALPS index than HCs (<i>p</i> &lt; 0.001), and both were associated with cognitive performance in the overall cohort(B = -4.7, SEM, 1.478, <i>p</i> = 0.002; B = 3.8, SEM, 1.789, <i>p</i> = 0.037) and could serve as independent predictors for AD (<i>p</i> &lt; 0.01). In AD patients with CSF data, CPV was negatively associated with estimated glomerular filtration rate (eGFR) (<i>r</i> = -0.402; <i>p</i> = 0.046), CSF amyloid-β (Aβ) 40 (<i>r</i> = -0.415; <i>p</i> = 0.039) and positively associated with Aβ42/Aβ40 ratio (<i>r</i> = 0.505; <i>p</i> = 0.01). CPV partially mediated the effect of kidney function on AD pathology while ALPS index did not.</p> Conclusion <p>CPV and ALPS index may serve as potential imaging markers for AD, and the CP was involved in the crosstalk of the kidney-brain axis.</p>