Abstract: The inhibition effect of carane-3, 4-diol in aqueous solution against the root and shoot growth of annual ryegrass(Lolium multiflorum Lam.) and rape(Brassica campestris) was investigated using a Petri dish culture method for the potential as water-based herbicides. The results of solubility test showed that carane-3, 4-diol was slightly soluble in water, while it could be made into water-based emulsion with a concentration more than 20 mmol/L by employing a small amount of hydrophilic organic solvents and surfactants. The results of herbicidal activity experiment showed that carane-3, 4-diol could inhibit the root and shoot growth of annual ryegrass and rape, which showed the concentration-dependent herbicidal activity. The half-maximal inhibition concentration values in aqueous solution against the root and shoot growth of annual ryegrass were 1.12 and 1.73 mmol/L, and the values that against the root and shoot growth of rape were 1.23 and 2.12 mmol/L, respectively. Additionally, carane-3, 4-diol showed higher herbicidal activity than that of natural monoterpenic diol p-menthane-3, 8-diol, as well as the slightly lower herbicidal activity than that of commercial herbicide glyphosate. It was expected to be further developed as a water-based botanical herbicide.