A review of the technique of direct growing high-quality InxGa1−xAs or InP buffer layers on GaAs substrates by metal-organic chemical vapor deposition (MOCVD) is given. This low-temperature growth method benefits the improvement of metamorphic device performance. In this work, a simple and novel method of directly deposited thin InxGa1−xAs or InP buffer layers (< 1 μm) on GaAs substrates is presented, instead of strained-layer superlattice, two-step, graded or CS (compliant substrates) methods, while maintaining low dislocations, high crystal quality, and uniform and mirror like surfaces. For the direct growth technique of InxGa1−xAs on GaAs, we found an excellent quality In0.54Ga0.46As buffer of rms surface roughness of only 0.686 nm by AFM and FWHM of 925 arcsec by XRD can be obtained at a low growth temperature of 440∘C with a constant Ga/Ingas partial pressure of 5. The superior results are mainly due to the use of low temperature growth technology. In addition, we also found this growth technology is available to directly grow InP buffer layers on GaAs. Experimental results conclude that the growth temperature of 480∘C in harmony with the V/III ratios range of 130–210 is a suitable window to directly grow InP on GaAs substrates.