In this paper, definitions of K automata, K regular languages, K regular expressions and K regular grammars based on lattice-ordered semirings are given. It is shown that KNFA is equivalent to KDFA under some finite condition, the Pump Lemma holds if K is finite, and KNFA is equivalent to KNFA. Further, it is verified that the concatenation of K regular languages remains a K regular language. Similar to classical cases and automata theory based on lattice-ordered monoids, it is also found that KNFA, K regular expressions and K regular grammars are equivalent to each other when K is a complete lattice.