Dynamic recrystallization (DKX) behavior in a newly developed Cu-Sn-P alloy was systematically investigated. Hot compression tests were performed on alloy samples having different crystalline conditions, i.e., as-cast coarse-grained polycrystalline and orientation-controlled bicrystals. Also tested were Cu-Sn-P alloys with varying Sn content. As a result of Sn addition, the Cu-Sn-P alloy was found to undergo DRX that is much delayed compared with that of a conventional Cu-P. The delayed DRX is considered to have increased the flow stress and strain required for processing the Cu-Sn-P alloy. When compressed under conditions that are close to the conditions of the actual operation, the alloy was found to exhibit a significantly inhomogeneous microstructure. This structure seemed to be refined and homogenized as a result of static recrystallization during the subsequent cooling after extrusion. It is concluded that the DRX in Cu-Sn-P alloy is dominated by discontinuous DRX governed by the annealing twins formed behind the migrating grain boundaries.%家庭用ルームエアコンやヒートポンプ式給湯器の熱交換器，および配管用の材料として，世界的にりん脱酸銅（JIS H3300 C 1220）が広く使われている。一方，近年のCO_2など高圧冷媒の採用や銅価高騰によるコストダウン要求の高まりから高強度鋼管が開発され，製品化されている。しかし，高強度鋼は銅管としては新しい材料であり，いずれもCoやSnなどが添加され，今までの純銅系のりん脱酸鋼とは押出性などが大きく異なることが経験的に知られていた。
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