Soil salinization has been causing crop yields reduction worldwide, which is a great threat to global agriculture. The study of salt tolerance-related genes is the basis of using biological techniques to improve crop plants’ salt tolerance. We extract the total RNA from young roots of shanlan rice, and then amplify HKT2 gene segment through PCR, to obtain a sequence of 1593bp. Then by building HKT2 gene overexpression vector, make HKT2 excessively express in Rhine Chlamydomonas CC124. Determine the salt tolerant ability of wild type Rhine Chlamydomonas and transgenic Rhine Chlamydomonas. The experimental results show that shanlan rice HKT2 expression products reduce the salt tolerance of Rhine Chlamydomonas.