A space mission called "Earth 2.0 (ET)" is being developed in China, which consists of six transit telescopes and one microlensing telescope and will be launched to the L2 halo orbit around 2027. The microlensing telescope has a diameter of 35 cm, a field of view of 4 square degrees and will be operated at the diffraction limit. Combined with ground-based microlensing telescopes (e.g., KMTNet) and space telescopes (e.g., Roman), ET will be able to measure the masses of more than 300 bound and free-floating planets and constrain their mass functions to uncertainties within 10%. The transit and the microlensing telescopes will constrain the statistical properties of terrestrial planets and their formation theory.