A secure communication is achieved by upper layer applications such as common key or public key cryptosystems in current transmission systems. However, the security is never exclusive and the multiplexing of security schemes is highly effective, so a secure transmission scheme on physical layer is also important. One of the typical physical-layer schemes is a chaos transmission which produces a secure, safe, wired or wireless communication. However, the main drawback of the chaos scheme is an error-rate performance degradation. We proposed a chaotic convolutional code which improved the performance in the tradeoff with decoding complexity increase. Here, in this paper, we focus on the diversity property of multiple-input multiple output (MIMO) and propose a chaos MIMO transmission scheme to achieve the secure on physical layer, low error-rate, and low complexity transmission. The joint MIMO detection and chaos decoding is done by maximum likelihood decoding (MLD) at the receiver. We will evaluate the performance of the proposed scheme by computer simulations.