Objective To investigate the effects of social/population factors, dietary patterns, and folate biochemical level on serum homocysteine(HCY) level in the elderly. Methods A total of 4319 elderly people (≥60 years) in Baodi District of Tianjin were selected as the subjects. Serum HCY >15 μmol/L was defined as hyperhomocysteine (HHCY), and the elderly were divided into HHCY group (n=1 477) and non-HHCY group (n=2 842). Dietary information was collected by food frequency method, dietary patterns were extracted by principal component analysis, and the effects of different dietary patterns on serum folate and HCY levels were analyzed. SPSS 25.0 was used for statistical analysis. Student′s t-test, One-way ANOVA or Chi-square test was employed for intergroup comparison based on data types. Results Compared with the non-HHCY group, the HHCY group was older with more males, higher BMI, and lower serum folate levels (all P<0.05). Three dietary patterns were extracted in the principal component analysis, among which the ovo-lacto vegetarian dietary pattern was beneficial to a decrease in serum HCY level and an increase of serum folate level (all P<0.001). The animal pattern was associated with a decreased serum folate level (P<0.001), but not significantly with serum HCY level. Beans dietary pattern was associated with the decrease of serum HCY (P<0.05), but not significantly with serum folate level. Conclusion It is suggested that the rural elderly in Tianjin should increase the intake of vegetables, fruits, eggs, dairy products, nuts and seeds, soybeans and other legumes in their daily diet but moderately reduce the intake of animal food and fried food, which is beneficial to reduce HCY and protect the cardiovascular and cerebrovascular health.