Two semi-bush lines of "Aehobag" (which is a local word meaning the elongated squash picked at green mature stage) lines, `Wonye #401` and `Wonye # 402`, were developed by the National Horticultural Research Institute, RDA in 1996. Cucurbita moschata has good flesh quality, but its vine growth habit hinders wide cultivation under structure. On the other hand, `Zucchini` varieties of C. pepo have bushy growth habit and better growth ability under the low temperature conditions, but its fruit flesh quality is inferior to that of C. moschata. To breed bush type squash with good flesh quality adapted to growing in the confined space under structures. Embryos from interspecific crosses between C. pepo `Ford Zucchini` and C. moschata `Seoulmadi`, were rescued by in vitro culture of halved ovules. In 1988, BC₁F₁ was generated by backcrossing with `Seoulmadi`, and the selected individuals were selfed 3 times (`89∼`91) to integrate bush genes. Second backcrossing to the BC₁F₄ was made in 1992. After 2 successive selfing of the BC₂F₄, `Wonye #401` and `Wonye #402` that had semi-bush growth habit and good flesh quality were selected from the BC ₂F₂populations. Vine length is slightly over 2 meters in both lines, internode length is about 4 ㎝ in `Wonye #401` and 3. 3 ㎝ in `Wonye #402`, and ratio of female flowers in the first 20 nodes are 35 to 40 % compared to 45% in "Zucchini" and 20% of `Seoul Madi`. Fruit starch content, the most important indicator of the eating quality, of 7. 5 % /dw in both lines are similar to that of `Seoul Madi`, compared to 4. 7 % of `Zucchini`. Both lines were released to commercial companies and the seed availability is regulated by a decree of the Rural Development Administration.