The facial nerve contains motor, sensory and parasympathetic fibers and has several branches in Fallopian canal in temporal bone. The facial nerve was supplied by the abundant vascularity and vascular anastomosis through the canal. The peripheral facial nerve paralysis might be resulted from injury of these vasculatures by some factors. Bell's palsy and Ramsay-Hunt syndrome is the most common cause of the classification in peripheral facial nerve paralysis. Because of diagnostic test of facial nerve branches may provide valuable informations and observations of treatment course, curable rate was very high. Author has analysed 52 cases of Bell's palsy among 101 cases of peripheral facial nerve paralysis treated at the Department of Otolaryngology, Kyung Hee Medical Center, from April 1981 to Sept. 1983. Author has analysed the material in the view of diagnostic classification of peripheral facial nerve paralysis, sex and age distribution, time of onset, relationship between NET, EGM, and result of NET, SR, LT and EGM after medical treatment. The result were as follow ; 1) Bell's palsy was the most common diagnostic classification in 101 cases of peripheral facial nerve paralysis. Diagnostic classification of 101 cases of peripheral facial nerve paralysis were as follow in order of frequences. Bell's palsy in 52 cases(51.4%), Ramsay-Hunt syndrome in 25 cases(24.7%), otogenic in 16 cases(15.8%), traumatic in 4 cases(3.9%). 2) The highest age incidence is noted in 3rd decade(16 cases, 30.7%) and then 4th, 5th, 2nd, 7th and 1st decade in order. 3) About the duration of onset of Bell's palsy, within 2 day was 14 cases(26.9%), within 2 weeks in 10 cases(19.2%) and then 3rd, 5th, 6th, 7th, 4th and above 2 weeks in order. 4) By NET in Bell's palsy, below 3.5mA difference was seen in 36 cases(69.2%), above 3.5mA difference in 10 cases(19.2%) and scale out in 6 cases(11.5%). 5) In relationship between NET and SR, below 3.5mA difference was seen in 36 cases(SR(+) in 1 cases, SR(-) in 35 cases), above 3.5mA difference was seen in 10 cases(SR(+) in 2 cases, SR(-) in 8 cases) and scale out was seen in 6 cases(SR(+) in 5 cases, SR(-) in 1 case). 6) In relationship between SR and LT, hypofunction of lacrimation was seen in 49 cases(SR(+) in 8 cases, SR(-) in 41 cases) and hyperfunction or normofunction was seen in 3 cases(SR(-) in 3 cases). 7) In relationship between SR and EGM, below 50μA by the EGM was seen in 8 cases(SR(+) in 2 cases and SR(-) in 6 cases) and above 50μA was seen in 44 cases(SR(+) in 6 cases and SR(-) in 38 cases). 8) According to topographic diagnosis, the most common site lesion was suprastapedial region(41 cases, 78.8%) and then suprachordal region(6 cases, 11.5%) transgeniculate region(3 cases, 5.8%) and infrachordal region(2 cases, 3.8%). 9) About the prognosis after 3 weeks of medical treatment : (1) By NET, 36 cases of below 3.5mA difference were increased into 42 cases after 3 weeks, 10 cases of above 3.5mA difference were changed into 5 cases after 3 weeks and 6 cases of scale out were changed into 5 cases after 3 weeks. (2) 44 cases of SR(-) were decreased to 35 cases after 3 weeks and 8 cases of SR(+) were increased to 17 cases. (3) LT and EGM were not significant tools in determination of prognosis.