Abstract: During the field survey made by the authors during 3 years(1981-1983),241 typhoid fever cases were diagnosed by means of blood and stool culture for Salmonella typhi and Widal's reaction Using self-made SPA-1a6elfed anti-serum against S.typhi and metbylene blue staining and urine samples absorbed with SPA to remove nonspecific agglutinating materials to perform coagglu tination reaction,229 ppsitive cases were found out among the above mentioned 241 patients. The positive accordance rate amounted to 95.02%. Control tests were also carried outin 241 normal persons and none was positive.