Abstract: Tense operatorsE(ever)andF(will)as well as their dual operatorsH(ever always be) andG (will always be) were introduced into lattice-valued propositional logic system LP(X), forming a lattice- valued tense propositional logic system LTP(X).It takes time axis as language circumstances. The properties of LTP(X)related to time and superposition of tense words were discussed. It was proved that semantic modus ponus (MP) and hypothetical syllogism(HS) rules hold in this logic system.