After more than 40 years theory research and industry paractice, evaporation-cooling technology has miade great breakthrough at the end of 20th centruy. On December Ist 1999. a 400MW evaporation-cooling hydro-generator was put to use in Chinese power system at lijiaxia power sation of Qinghai province. Industry experience shows that evaporation-cooling technology keeps the advantages of the old ones and overcome the main disadvantages of them. So it has many prospective applications in 21st century.