Curing catalyst used for curing polymer, method for producing same, moisture-curable composition, and method for producing cured product

A method of producing a moisture-curable composition comprising a step of producing a curing catalyst [B] and a step of mixing the curing catalyst [B] with a polymer [A] having a reactive hydrolyzable silicon-containing group, wherein

• the step of producing the curing catalyst [B] comprises a step of forming a complex by reacting a titanium compound [B1] with an ammonium hydroxide [B2] in a mixture obtained by mixing the titanium compound [B1] and the ammonium hydroxide [B2] to obtain a catalyst composition, wherein
• a molar ratio of the titanium compound [B1] to the ammonium hydroxide [B2] in the mixture is 1:1 to 2.8:1,
• the titanium compound [B1] is represented by Chemical Formula (1),
• the ammonium hydroxide [B2] is represented by Chemical Formula (2),
• (R1—O)nTi-A4-n (1)
• in Chemical Formula (1), R1 is a substituted or unsubstituted hydrocarbon group, n is 1 to 4, A is a β-diketone group,
• in Chemical Formula (2), R2, R3, R4 and R5 represent substituted or unsubstituted hydrocarbon groups having 1 to 8 carbon atoms, which are the same as or different from each other, and X represents a hydroxyl group.