Nucleosynthesis yield is a very important parameter of the Galactic chemical evolution model.We adopt the same method as Tsujimoto to derive the r-process yields of various mass SNe Ⅱ at low metallicities from the new observed [Ba/Fe]-[Fe/H] trend.Furthermore,we present a new formula of r-process nucleosynthesis yields.We also consider the various neutron sources and set up four cases,namely A,B,C and D to calculate the abundance evolution of Ba peak elements in the solar neighbourhood.Our results show that the r-process could be associated with a secondary event in massive stars(i.e.,18M ＜ M ＜ 50 M).Therefore,the r-process could be associated with a secondary event in massiye stars.Both the neutron source and the seed nuclei must be freshly manufactured by the stars instead of depending upon the initial metallicity abundance.