A high isolation electromagnetic transmitter and receiver is revealed. An isolation portion, a first antenna body and a second antenna body are extended from and formed over a grounding portion. The isolation portion is extended to and formed between the first antenna body and the second antenna body. A parasitic element corresponding to the isolation portion is disposed between the first antenna body and the second antenna body. The isolation portion is T-shaped. The parasitic element is reverse T-shaped and arranged over the grounding portion. The structure is simple and able to be applied to the design of planar printed antennas. The production is easy and the cost is reduced. The volume is minimized to be used in various mini wireless mobile communication devices. No interference occurs even that the first and the second antennas are close due to good isolation.