The tensile breaking properties of fish myosin gel were examined together with the investigation of the kinds of cross linkages of the heat-induced myosin gel. Sample myosin was extracted from croaker Nibea mitsukurii and was ground with 0.6M KCl. It was then heated to gel at 80°C for 20 min. The breaking strain along with the breaking stress were measured in concentrations ranging from 70 to 120mg myosin/g gel. The former was a maximum at around 85mg/g gel while the latter increased with a rise in myosin content. The breaking strain of myosin gel to which urea and guanidine hydrochloride was separately added decreased with the concentration of any reagents. Similar results were observed when sodium dodecylsulfate, a kind of surfactant, was added. On the contrary, in the case of the addition of 2-mercaptoethanol as a reducing reagent of the disulfide bond, the breaking strain was almost the same as that of the control. From the set of results, the hydrogen bond along with hydrophobic bond were found to play principal roles in the gellation of the myosin, while the disulfide bond contribution was negligible.