Abstract: Metal-organic frameworks MIL-100(Fe) catalyst was prepared by hydrothermal method using ferric nitrate and benzene tricarboxylic acid as raw materials. Its structure was characterized by XRD, SEM and BET. The catalytic performance of MIL-100(Fe) for n-valeraldehyde self-condensation to 2-propyl-2-heptenal was evaluated. The components existing in the reaction system were identified by GC-MS analysis. The effect of reaction conditions on 2-propyl-2-heptenal synthesis was investigated and the suitable reaction conditions were determined as follows: a weight percentage of MIL-100(Fe)=15% (benchmarked against the quality of n-valeraldehyde, the following is the same), reaction temperature of 130 ℃, and reaction time of 8 h. Under the above conditions, the conversion of n-valeraldehyde was 73.5%, and the yield and selectivity of 2-propyl-2-heptenal were 63.2% and 86.0%, respectively. The MIL-100(Fe) catalyst could be reused for four times without a significant loss in its catalytic activity. XRD, FTIR analysis showed that the catalyst structure did not collapse. Lastly a possible reaction network of n-valeraldehyde self-condensation catalyzed by MIL-100(Fe) was established based on speculation of the side-reactions.