1-Hydroxy-2(1-methylimidazol-2-y1)ethylidene-1,1-bisphosphonic acid(HMIBP) is synthesized by four steps from the raw material 1-methyl imidazole.The first intermedia is prepared without extra pressure;The third and the target compound are both synthesized via one step,and pollution is reduced and the process is simplified.HMIBP is identified by IR,elementary analysis,MS and NMR.