Objective. To investigate the changes in the levels of homocysteine (Hcy) and C-reactive protein (CRP) in patients with Alzheimer's disease (AD) and analyze their correlation with cognitive and UPDRS functions. Methods. A total of 50 patients with AD admitted to our hospital from January 2020 to March 2022 were selected into the research group, and 50 healthy subjects were selected as the control group. The levels of Hcy and CRP of the two groups were analyzed, and the patients’ cognitive functions were evaluated with the Mini-Mental State Examination (MMSE) score and UPDRS function scoring. The correlation between the changes in levels of Hcy and CRP, and cognitive and UPDRS functions in the two groups was compared and analyzed. Results. The levels of Hcy and CRP of the research group were higher than those of the control group, with statistical significance (
P
<
0.05
). The following were evaluated for the scoring of patients’ cognitive functions in the research group: orientation, attentional computation, short-term memory, language ability, visuospatial ability, instant memory, and MMSE total score, all of which were lower than those in the control group, with statistical significance (
P
<
0.05
). UPDRS I, UPDRS, UPDRS, and total UPDRS score in the research group were higher than those in the control group, with statistical significance (
P
<
0.05
). In the research group, the higher the Hcy level, the lower the MMSE score, with a negative correlation (
P
<
0.05
), and the higher the Hcy level, the higher the UPDRS score, with a positive correlation (
P
<
0.05
). And, the higher the CRP level, the lower the MMSE score, with a negative correlation (
P
<
0.05
); the higher the CRP level, the higher the UPDRS score, with a positive correlation (
P
<
0.05
). Conclusion. Compared with the health subject group, the levels of Hcy and CRP were higher in patients with AD, and their changes had a negative correlation with cognitive functions in patients with AD, and a positive correlation with UPDRS in patients with AD, with high clinical values in evaluating cognitive and UPDRS functions.
