A tunable long term evolution antenna comprises a feeding portion, a grounding portion, a first radiation portion, a second radiation portion and a coupling radiation portion. The shape of the first radiation portion is a strip. Two terminals of the strip respectively are a first terminal and a second terminal. The first terminal is connected to the feeding portion and the grounding portion. The second radiation portion is connected to the grounding portion and the first terminal of the first radiation portion. The coupling radiation portion has a switching terminal coupled to a switch, a low frequency coupling portion and a high frequency coupling portion. The switch controls the switching terminal to be coupled to the ground or floating. The tunable long term evolution antenna operates in a LTE technology mode or a 3G mode depending on the switching terminal is coupled to the ground floating.