Abstract: Can logic be revisable? May logical truth be false? Recently some scholars have carried out related intense discussions. The controversy that logic may be revisable is essentially that of the connotation and extension of logical concept, while the controversy that the logical truth may be false is actually that of the understanding, which conceals a question: Does truth exist in logic? If the logical truth is seen as logical valid formulae, and the logical truth is not considered as truth, the truth will be denied inevitably to exist in the logic. The logical truth should not refer to the logical valid formulae in a system, but to the universal valid formulae inside and outside the system, therefore the logical truth as one form of truth can not be false and truth exists in logic.