Objective   To analyze the relationship between nutrition, related factors and brain tumors.

  Methods   Pared case-control study was used to calculate the consumption of nutrition and N-nitrosamine, and to analyze the risk of factors, multiple factors and interaction.

  Results   In factors analysis, smo king was related to brain tumors in men only(OR=2.51, 95%CI: 1.070~5.873).Protein, fat, carbohydrate, cholesterol, fiber and carotene are the protective factors in two kinds of tumor.N-nitrosamine was the risk factor to brain tumor.With increasing levels of consumption of N-nitrosamine, the Odds Ratioincreased.For the results of multiple logistic regr ession, cholesterol, smoke, N-nitrosamine and interaction between carotene and N-nitrosamine were in to models.With carotene-stratified, there was a significant relationship between N-nitrosamine and brain tumors with carotene only at the lowest level of consumption of carotene.

  Conclusion   Protein, fat, carbohy drate, cholesterol, fiber and caro tene are the protective factors in two kinds of tumor, but cholesterol and carotene has more protective.N-nitrosamine is a risk factor, the risk increasing with itcs intake incr eased.Carotene may be has the function to reduce the risk of N-nitrosamine to brain tumor.