PROBLEM TO BE SOLVED: To provide a resin wire for a greenhouse excellent in the workability for making nodes (a winding property), and in the strength (the tensile strength and drawing strength when the wire is wound).SOLUTION: The resin wire for the greenhouse is made of a monofilament of a resin composition containing thermoplastic polyester and an organic ultraviolet absorber. The monofilament of the resin wire satisfies the following conditions: (a) the tensile strength after extension is 350-600 MPa； (b) the coefficient of extension is 5-25%； (c) the circularity degree is at least 80%； and (d) the brightness value (Y value) is at least 12.5.【課題】結節作業性（巻き付け性）、強度（引張り強度、巻き付け時の引き出し強度）が優れた温室用樹脂線を提供する。【解決手段】熱可塑性ポリエステルと有機系紫外線吸収剤を含有する樹脂組成物のモノフィラメントからなる温室用樹脂線であって、前記モノフィラメントが、下記の要件（ａ）～（ｄ）を満たすものである温室用樹脂線。（ａ）延伸後の引張強度が３５０～６００ＭＰａ（ｂ）伸び率が５～２５％（ｃ）真円度が８０％以上（ｄ）明度値（Ｙ値）が１２．５以上【選択図】なし
