0ptimum temperature of seed gemination of Cuscuta australis R. Brown lies at 25-28℃. Matured Cuscuta seeds germinate better than immatured ones. Within the limit of experiments, there was no relation on the germinability between the dark and light plots. Cuscuta seeds germinated on the filter paper with water in Petri dishes can grow until 3-5cm of the stem length. After placing the sucker of C. australis on Vigna catiang, stem of Vigna dies under the sucker placing point, Germinating of the combined sowing of seeds of C. australis with the seeds of Pisum sativum L. var. arvenese Poir and macerated seed juice of V. catiang attacked by C. australis after placing the plant cutting on 0.0001% solution of Uranine(Fluorescein sodium) for 24 hours, under fluorescent microscope, C. australis seemed to absorb the nutrients from the host plants. Effect of some herbicides on the seed germination of C. australis was examined. Stam(3, 4-dichloro-propionanilide), Gracide(2-[1-cyclohexenyl]-cyclohexanine), and Chloro-IPC(isopropyl-m-chlorocarbanilate) showed the browning of the root tip. Chloro-IPC showed the inhibition of stem greening. Chloro-IPC and Stam showed the inhibition of stem growth of C. australis.