The effects of part substitution of Zr by Yb（Yb=0

0.01%

0.02%

0.03%

and 0.04%）on the mechanical and electrical conductive properties of Al-0.2Sc-0.04（Zr

Yb）alloys were investigated.It is found that with only 0.01% and 0.02% Yb substituted for Zr

Al-0.2Sc-0.04（Zr

Yb）alloys exhibit an apparent ageing-hardening peak.The optimum ageing temperature is around 330℃.For the alloys partially substituted by 0.01% and 0.02% Yb

the corresponding yield stresses reaches 188.1and177.5 MPa

while the tensile strength is 212.9and 207.3 MPa

respectively.Excessive substitution of Zr by Yb

the decrease of mechanical properties can be observed.The results show that the electrical conductivity of the alloy can further improved by cold rolling.Al-0.2Sc-0.04（Zr

Yb）alloys with the desirable comprehensive properties can be obtained by the part substitution of Zr by 0.02% Yb.