Nine polycarboxylic acids (PAs) were employed in silica sol to offer an alternative approach in improving washing durability of the hydrophobic cellulose fabric by the sol-gel method. Polycarboxylic acids played a twofold role since they work not only as catalysts in hydrolyzing silica precursor hut more importantly as cross-linkers to bind silica coating to cellulose substrate. Washing durability of hydrophobic cellulose fabric finished by the sol-gel method was obviously enhanced. The polycarboxylic acid with the proper number of carboxylic acid groups and distance between the terminal carboxylic acid groups could enhance the washing durability of the hydrophobicity of the cotton fabric by the sol-gel method. 1,2,3,4-Butanetetracarboxylic acid (BTCA) led to the best durability of hydrophobic cellulose fabric with a water contact angle of 138.6 degrees (recovery percentage 96.5%) after washing 30 times. The effect of BTCA on durability was also characterized by scanning electron microscopy (SEM). This study suggested that the organic-inorganic sol-gel hybrid using PA as a catalyst is appropriate for achieving a durable hydrophobic cellulose fabric.