For the purpose of developing Korean Herbalogy with the plants of Oleceae which grow wild and is planted in Korea, the these and writings on herbalogy, from literature of successive generations, have been thoroughly investigative and the results obtained were as follows: 1. According to sum of 101 species in Oleaceae family they were classified into Syringa genera 29, Ligustrum genera 24, Fraxinum genera 20, Osmanthus genera 20, Forsythia genera 8, Albeliophyllum genera 8. Thus it was noticed that Syringa genera was the main kind, some 29% in total. 2. There were totaled 19 genera and 101 species in Korea and among them modecinal plants are 6 genera, 28 species, in total but the number of species may be added because of similar plants. 3. According to the oriental name which can be used for medical purpose, the medicinal plants beloning to the Oleaceae fimily were classified as Fructus 3, Folium 5, Radix 4 Flos 3, Cortex 4, Lignum. Thus it was noticed that Folium was the Main kind. 4. According to the number of species of the origin plants about each chinese materia medicals, they were classified into FRUCTUS FORSYTHIAE 6, FRUCTUS LIGUSTRI 3, CORTEX FRXINI 2, FRUCTUS SYRINGA 3, FRUCTUS LIGUSTRUM OBTUSI FOLIO 2, FLOS JASMI NUDIFIORUM 1, FLOS JASMINI SANBAC 1. 5. According to nature and foavour of medicinal plants, they were classified into cold, cool ; 9, balance ; 6, wormth ; 3. Thus it was noticed that cold, cool is the main in nature and flavour of medicinal plants unidentified 3. 6. According to the Properties and Principal Curative action, they were classified into, clearing up heat and toxin 7, medicines for rehulating the flow of gi and allevating pain 3, resolving phlegm and cough, invigorating kidney and liver 2, clearing up heat and moisture, healthiness eleminating bloodstasis and aleviating pain, grgulating the flow of gi and invigorating blood circulation 1 each. 7. Comparing o whole medicinal plants 20 kinds, toxic durgs include minor toxin were 3 kinds, 7% of the whole. Thus toxic durgs were rare. From this result, it was revealed that the plants for medical purpose in Oleaceae was 28 kinds of the whole, in which Folium was mostly abundunt, were distributed (over) the whole country (widly) that it will be used for clinical treatments more easily. For (about) unidentifical drugs, it is considered that many experiments and clinical approaches must be continued.