Frame rate in ultrasound imaging can be dramatically increased by decreasing elements for transmitting in Synthetic Aperture (SA) imaging techniques. But there are two main drawbacks, which are the low Signal-to-Noise Ratio (SNR) and the motion artifacts, degrade the image quality. Coded excitation extends the bounds of this tradeoff between SNR and frame rate by increasing SNR through appropriate coding on transmitting stage and decoding on receiving stage. A new method named the Space Coded Synthetic Aperture (SCSA)imaging is introduced in this paper. Different from traditional code scheme in which transmittal signals are encoded and echo signals are decoded, the new method encode the low quality images which is focused in receive due to one element transmits . Phase code can be used in the method, such as golay code and bark code. Spatial autocorrelation is used to be the decoding scheme and the maxim of autocorrelation is the image value, so the final image can be get directly. The method has been evaluated in simulations with Field II, in which the point-spread functions were simulated for different depths for a 3.5 MHz linear array transducer with 64 elements and16 bit golay code is used, the simulation result shows that compared with traditional SA imaging, it can increase Peak-Side- Lobe (PSL) level by 11dB,and decrease Full Width at Half Maxim (FWHM) by 0.6mm at 40mm depth. The frame rate increases by 4 times. The method has been evaluated by experimental data. In experiment, 32 bit golay code is used, and the result shows that SCSA can increase PSL level by 19dB and improve image quality obviously. Besides, compared with traditional signal-coded scheme, SCSA can get high robustness and high frame rate. Finally, SCSA decrease the transmittal times and does not change transmittal signal, so it can be used in the commercial system easily.