The paper summerized the result of data obtained from 1,124 premature infants delivered at the maternity ward Soo-Do medical college observation cover the period from January 1962, through 1963. Result are as follows. 1) Incidence of premature deliveries is computed at 10.3 per 100 live births 2) Seasonal variation shows that incidence is the highest in autumn, followed by winter, summer and spring in order of prevalence. 3) 89.2% of live births ouuned during 29th∼32th week of gestation is premature infants, 65.9% in 33rd∼36th week, 27.8% in 37th∼38th week, 3.7% in 39th∼40th week of pregnancies. 4) Among premature infants, femalis markedly exceedes the male in incidence 100 : 78.5. 5) Premature deliueries are most prevalent among wives aged under 20 and those over 35 years among mother with parity over 5 incidence of prematurity is markedly higher than others. 6) Of prinigravida, incidence of premature deliveries is lowest for mother aged 25∼29 9.3% and 20% for those aged 35 or beyond, while the incidence is the Highest among multipara aged 20∼ 24(28.6%) and those 40 year or over (19.2%). 7) Mother with previous episodes of prematurity Tend to have subsequent premature deliveries: 20 percent of mothers who have had Two previous premature deliveries underwent premature deliveries. 8) Of 31 Twins (including 1 case of triplet pnegnuncy) premature infant were 14 cases. 9) About one third of new borns delivered among eclamptic mothers were prematuer.