Objective: Gastric cancer is the fourth most common malignancy and the second most prevalent cause of cancer induced death in the world. Both genetic and environmental factors are involved in the development of this cancer. Epidemiological and nutritional studies have indicated that folate status modulates the risk of developing cancer and On the other hand apoptosis has been reported to play a decisive role in precancerous changes.The aim of this cross-sectional study was to investigate whether there is any relationship between serum folic acid levels and apoptosis (as an early indicator of gastric cancer changes) in human gastric mucosa and find the best fit or exact relationship between them. Materials and Methods: Consecutive patients over 18 years old, referred to 2 hospitals in Tabriz, Iran to undergo an upper gastrointestinal endoscopy and 62 subjects were finally enrolled. We measured the levels of folic acid in serum and Apoptosis was detected by TUNEL technique. We tested polynomial curve to find the best fit between them. Results: Our study indicates the relation between level of folic acid in serum and apoptosis in human gastric mucosa was non linear in contrast with other study. Conclusion: The final and the best fit curve was:apoptosis =1.898+1.57*10-10(B9)8.