Abstract: The paper takes marine organisms,i.e.mussel Mytilus crassitesta lischke,clam Arca subcrenatd lischke,prawn Penaeus orientdlis kishinouye,Pendeus pencillatus Alcock,as well as brown algae Laminaria Tdponica Aresh,green algae Enteromorpha intestinalis Link and phytoplankton platymonas sp.as material for experiment,on the understanding that certain water temperature,concentration of radionuclides in 5×10^-8Ci/l,make use of the method of feeding radionuclides in the laboratory experiment and determine concentra tion factors of ⁶⁰Co and ¹³⁷Cs in them.