PROBLEM TO BE SOLVED: To provide a gravitropism modifier having effects on creeping property of plants or sugar content of fruits.SOLUTION: There is provided a gravitropism modifier containing cis cinnamic acid and/or a cinnamic acid analog represented by the formula (1) as active ingredients. (1), where A is cyclic hydrocarbon which may have a substituent, X is a bound or a C1 to 5 substituted or unsubstituted hydrocarbon chain, Ris H, a hydroxyl group, an alkali earth metal salt or the like, Ris a bond or a C1 to 5 substituted or unsubstituted hydrocarbon chain and Rand Rare H or together form C5 to 8 cyclic hydrocarbon.SELECTED DRAWING: Figure 6【課題】植物の匍匐性や果実の糖度等に影響を及ぼす重力屈折性調節剤の提供。【解決手段】シス桂皮酸及び/又は下式(1)で示される桂皮酸類縁体を有効成分として含む重力屈折性調節剤。［Ａは置換基を有してもよい環状炭化水素；Ｘは結合又はＣ１～５の飽和又は不飽和炭化水素鎖；Ｒ１はＨ、水酸基、アルカリ土類金属塩等；Ｒ２は結合又はＣ１～５の飽和又は不飽和炭化水素鎖；Ｒ３及びＲ４はＨ又は共に形成するＣ５～８の環状炭化水素］【選択図】図６
