Nalco binary or ternary retention/drainage aid (N2 or N3), and starch was used to form retention system, in which different dosages of four kinds of filler were fixed, and then the opacity and other indicators of test paper were analyzed comparatively. The results showed that N3 has the best retention for all the four kinds of filler, and when the imported light calcium content 15 kg, the opacity of ultra low ration newsprint is 97.40%, with opacity increase of 2.74%; when using N2 and Guo Li light calcium content 20 kg, the opacity of ultra low ration newsprint is 96.40%, with opacity increase of 2.58%; considering production technology and cost factors, the best filler combination to improve the opacity of ultra low ration newsprint is " N2 aids + Guo Li filler ".