The HaCaT cells were collected. In the proliferation function experiment， the HaCaT cells were divided into experimental groups （added with different concentrations of Astragalus Injection） and control group （without drugs）， at the same time， blank group （without drugs and cells） was set up. The effective concentration of Astragalus Injection was determined by cell counting method.The HaCaT cells in experimental groups were incubated for 24， 48 and 72 h after adding different concentrations of Astragalus Injection with two times gradient dilution， and the proliferation rates of HaCaT cells in various groups were detected by CCK-8 method. In the adhesion function experiment， the HaCaT cells in experimental group were treated with 1.0 g·L^－1 Astragalus Injection and the HaCaT cells in control group were not treated with Astragalus Injection. After cultured for 24 and 48 h， the expression levels of β- catenin mRNA in the HaCaT cells in two groups were detected by qPCR method； after cultured for 48 h， the expression levels of β-catenin protein in the HaCaT cells in two groups were detected by Western blotting method.

The proliferation function test results showed that compared with 0，0.01， and 0.10 g·L^－1 Astragalus Injection groups，the proliferation rates of the HaCaT cells in 1.0 g·L^－1 Astragalus Injection group were decreased after treated for 24 and 48 h （P<0.01）. The HaCaT cells were incubated with 2 times concentration gradient dilution of Astragalus Injection （ 0， 0.5， 1.0， 2.0， 4.0， 8.0， 16.0 g·L^－1）for 24， 48， and 72 h， compared with control group， the proliferation rates of HaCaT cells in 1.0 g·L^－1 Astragalus Injection group were decreased after treated for 24 and 48 h （P<0.05）， the proliferation rate of HaCaT cells was increased after treated for 72 h（P<0.05）. In the adhesion function experiment， compared with 0 g·L^－1 Astragalus Injection group， there was no significant difference in the expression level of β-catenin mRNA in the HaCaT cells in 1.0 g·L^－1 Astragalus Injection group after treated for 24 h （P>0.05）；after treated for 48 h， the expression level of β-catenin protein in the HaCaT cells in 1.0 g·L^－1 Astragalus Injection group was decreased significantly （P<0.01）.

The mechanism of Astragalus injection in the treatment of psoriasis may be related to the inhibition of proliferation of human KC and the expression of adhesion factor β-catenin. As a single factor， Astragalus Injection could inhibit the proliferation of HaCaT cells and reduce the expression of β-catenin protein，and the inhibitory effect may decrease with the prolongation of time.