The present invention relates to a novel crystalline modification of fipronil, to a process for the preparation of the same, to pesticidal and parasiticidal mixtures and compositions comprising said crystalline modification and to their use for combating pests and parasites.本發明係關於一種氟蟲腈(fipronil)之新穎結晶修飾物,一種用於製備該結晶修飾物之方法,包含該結晶修飾物之殺蟲及殺寄生蟲混合物及組合物及其用於抵抗害蟲及寄生蟲之用途。