We developed a tissue adhesive consisting of biomolecules and a citric acid derivative (CAD) with active ester groups. To apply it biomedically, however, gelation time and gel strength must be different depending on the organ and injury. In this study, we added ionic salts or organic solvent to adhesive precursor solutions to modify adhesive properties, such as hardening period and strength. We measured gelation time and mechanical strength of gels under different conditions using a rheometer. We found that adding divalent anions and dimethyl sulfoxide (DMSO) shortened gelation time and increased mechanical strength.