Abstract: A method and a synthetic danger predicting and disaster preventing monitor system in which waterworks pipelines laid around under the ground or through a structure are employed in their entirety for a synthetic danger predicting alarm sensor to thereby predict a variety of occurable trouble, discover a sign of disastrous incidence early before a great accident results, and locate the place at which trouble occurs so that trouble remedying works are completed before a resultant great accident happens. Both end portions of piping 1 positioned across each of a great number of specific intervals (Nos. 1 to N) set at required portions of water distributing pipelines laid under the ground or through a structure are fitted with synthetic sensors S provided with detector portions for sound, radiation, heat, mechanical strain, electricity, magnetism and vibration.