It is interesting to survey the relationships between the otolaryngological troubles and their school credits, and body development in growing ages. Through the medical survey and question papers, we had studied in 1,700 students of 4th, 5th and 6th grade in rural primary schools, where they have undergone a little medical cares in contrast with urban primary schools. The results are as follows : 1) In the measurement of body building, boys are larger than girls under 13 years of age, but girls larger after 13 years of age. The rural students are larger than the urban at 8 and 9 years of age, but after 10 years of age, they are smaller in all measurements. 2) In the measurement of body building, there are no significant differences between healthy students and students with otolaryngological trouble. 3) Otolaryngological trouble are more frequent in the poor living class. 4) These troubles are more frequent in the cases of poor appetite, unbalanced diet, lack of meat or fishes, well-water drinking. 5) The students suffered from these troubles are easily tired, frequently dream, easily catch cold, and are more frequently absent from school in contrast with healthy students. 6) Among 88 tonsillectomy cases, 88.64% had subject improvements after operation. 7) In their school credits, the rate of highly ranked students are most in healthy, the next sinusitis, and the third tonsillitis, and so least in otitis media patients.