© 2020 The Japan Mendel Society.In this study, the antimutagenic effect of Rosa canina (rosehip) infusion against to mutagenic effect of the herbicide linuron was investigated on meristematic root cells of Allium cepa (onion) by Allium test and flow cytometry method. In this context, firstly, roots of A. cepa were treated with 0.1 mg mL-1 linuron for 12 and 24 h. Then the roots were recovered by R. canina infusion for 12 and 24 h. In a result of Allium test, depending on the exposure time of linuron, it was determined linuron suppressed to mitosis in meristematic root cells and caused disturbed chromatin, sticky chromosomes, c-metaphase, chromosome bridges, vagrant chromosome abnormalities in meristematic root cells. In addition, linuron was found to inhibit DNA synthesis in S-phase of the cell cycle with flow cytometric analysis. On the other hand, it was found that the infusions of R. canina have activated DNA synthesis, arranged mitotic cell division, and reduced chromosomal abnormalities of linuron. Thus, protective effect and healing of the negative effects in mitotic cells of R. canina infusions against to the linuron toxicity on cell division was revealed.