The monolithic adsorbent is a key part of an adsorptive rotary dehumidification system. It is usually prepared by dip-coating the adsorbent on glass fiber paper. In this study, a new in situ strategy for synthesis of an aluminum fumarate (A520) metal-organic framework monolithic adsorbent on glass fiber paper is introduced. The influences of the mole ratio of fumaric acid to H2O, the reaction temperature and time on the crystal phase, the pore structure, and the adsorption performance of the monolithic adsorbent are systematically discussed. The morphology of the adsorbent was characterized by scanning electronic microscopy, and the adsorption and desorption performances were evaluated by dynamic vapor sorption and differential thermogravimetric analysis. The results showed that under the conditions of a mole ratio of fumaric acid to H2O of 0.02, reaction temperature of 50 degrees C, and reaction time of 60 min, the obtained A520 monolith exhibited the highest BET surface area (740.15 m(2).g(-1)) and high adsorption capacity (0.3906 g.g(-1)). The monolithic adsorbent carries about 76% A520 powder with the advantages of a facile fabrication process, high adsorption capacity, rapid adsorption rate, and low desorption temperature, providing guidance for the fabrication of a highly efficient desiccant dehumidification wheel.