This paper presents a new method for speech coding at rates around 1.2 kbps based on STRAIGHT, a high quality speech analysis-synthesis method. For encoding spectral information, Modified Restricted Temporal Decomposition (MRTD) based vector quantization is used, where MRTD is a method of temporal decomposition for line spectral frequency parameters. Meanwhile, pitch and gain parameters are coded using linear and spline interpolation, respectively. Subjective test results indicate that the performance of the proposed speech coding method is close to that of the 4.8 kbps US Federal Standard (FS-1016) CELP coder.