Interferons are very effective species specific glycoprotein which has antiviral, immunomodulatory and antiproliferative properties. Fibroblast interferon (F interferon, 1FN-$\beta$) was produced from FS-4 cell line by superinduction method with treatment of synthetic poly I:poly C and various inducers. Produced interferon had apparent antiviral activity against the challenge of Indiana-type vesicular stomatitis virus (VSV). To select nontoxic and safe inducers, the extracts of natural products that were known as anticancer substances were tested interferon-induced capacity. But all of them were ineffective to induce interferon. For enhancement of uptake of poly I:poly C into the cells, $CaCl_2$ and DMSO were treated to cells. But the result was not encouraged. Denaturation of poly I:poly C had decreasing of inducing activity and priming effect of cells with small amount of interferon was also observed. When polyanion material, especially heparin, was treated to cells after removing of antimetabolites, the level of interferon was two or three times than that of normal superinduction. It was thought that the competition effect of heparin was in shutoff mechanism of interferon mRNA. Interferon and polyanion materials were treated to cells together. At this time, antiviral activity of interferon was slightly diminished because the polyanion substances are nuclease inhibitors.