Abstract: Seaweed oligosaccharides degraded from the seaweed polysaccharides are a series of oligosaccharide frag-ments. Seaweed oligosaccharides are characterized by lower molecular weight, better solubility, lots of biological activi-ties, compared with seaweed polysaccharides, thus they has a broad application prospest in agricultural production. The present study was conducted to summarize research advances in the application of seaweed oligosaccharides in remediation of contaminated soil and promotion of plant growth, and discussed several problems of application of seaweed oligosaccha-rides. It was found that the application of seaweed oligosaccharides in soil remediation was restricted due to the opposite effects of seaweed oligosaccharides on heavy metals in soil. The mechanism of soil microorganisms on the seaweed oligosaccharides and heavy metals complex was still not clear. There were limitations in the pratical application of seaweed oligosaccharides as plant resistance inducer. Therefore, the application of seaweed oligosaccharides should be focused on in future, as follows:the reasonable dosage of seaweed oligosaccharides and the appropriate way of remediation will be de-termined by the soil pH value and heavy metal contaminations degree. Meanwhile , seaweed oligosaccharides will be used in combination with other inducers or fungicides to overcome the limitations. Furthermore , seaweed oligosaccharides can also be used as new fertilizer additives to promote their further application in agriculture.