Abstract: The foreseeability principle requires patent applicants to include all equivalents that can be foreseen at the time of filing a patent in the claims, otherwise they may not be covered by the principle of equivalence. Although the foreseeability principle has the function of making the rights boundary of the patentee clearer, the rule is too restrictive to the principle of equality, which is contrary to the current industrial policy of encouraging R&D and investment of high-value invention patents in China, and it has no practical feasibility. Therefore, whether the application of the foreseeability principle in China's judicial practice remains to be further studied.