This experiment was conducted to study the possibility of soiling crop production utilizing the winter fallow fields in the Taekwanryong area, and determine the appropriate variety and the proper time of sowing and cutting. Cultivated winter rye (Secale cereale L.) of the Korean native variety and the Elbon variety introduced from the United States of America were sown at intervals of about 10 days according to the treatment plan from the latter part of August to the first decade of November 1979 on the experimental field(820m above sea level) located Hoengke-ri Toam-myon Pyongchang-gun Kangwon-do, Korea. The plots sown earlier than the latter part of September were divided into two groups; the one group was consisted of plots cut in that autumn season one time and in the following spring season one time and the other group was consisted of plots cut not in that autumn season but in the following spring season one time. The results obtained were summarized as follows: 1. If the soiling winter rye is grown as a second cropping on the winter fallow fields of potato, corn or vegetables, it seems that there will be no inconvenience in sowing the vegetables at proper time in the following .spring season; yet if potato or corn is expected to sow, its sowing date should be delayed about 20 days behind the proper sowing rime. 2. In the Korean native variety, the plot marked the highest yield of dry matter with 7.15t/㏊ was the plot sown early in September and cut in tie autumn and the following spring one time respectively. 3. In the plots sown earlier than the middle of September, the plots cut in the autumn season showed remarkably higher dry matter yield than the plot not cut in that season (P$lt;0.05). 4. In the plots sown late in September, the plot undergone an autumn cutting presented significantly lower yield in dry matter production than the plots not undergone the autumn cutting. 5. Of the plots not undergone the autumn cutting, the plots sown late in September displayed the highest yield marking 5.24 t/㏊ in the Korean native variety and 5.46 t/㏊ in the Elbon variety. 6. In dry matter yield, the Korean native variety produced 3.96∼7.15 t/㏊ when it was sown from the latter part of August to the middle of October and cut lastly in the latter part of May next year with an autumn cutting in case of being sown earlier than the middle of September; on the ether hand the Elbon variety brought forth 4.70∼5.46 t/㏊ when it was sown from the latter part of September to the middle of October and cut also lastly in the latter part of May next year. At this juncture, the both varieties produced more dry matter as the sowing date was getting earlier. 7. All the plots sown from the latter part of August to the latter part of October were at heading stage in late May having no relation to the sowing date. Accordingly it seemed that the proper time of last cutting of those plots fell on the latter part of May. 8. It was observed that the Elbon variety displayed better wintering record than the Korean native variety. 9. In dry matter yield, the Elbon variety was higher than the Korean native variety by 4.2∼70.6% (P$lt;0.05) when the both varieties were sown from late September to late October. The differences between these two varieties grew larger as the sowing date got later. 10. In plant length, the Elbon variety had a tendency to present shorter length in comparison with the Korean native variety. 11. Dry matter percentage measured at the last cutting was 13.9∼18.2% in the Korean native variety and 13.5∼16.4% in the Elbon variety. 12. It was found that the plots sown before the middle of September made apparently poor record in wintering and dry matter yielding when they were not undergone an autumn cutting, on the contrary the plots sown late in September revealed manifestly fine record in wintering and dry matter yielding when they were not also undergone the autumn cutting.