To evaluate haemolytic activities and adjuvant effect of Panax notoginseng saponins (PNS). The haemolytic potential of PNS and its effects on the humoral and cellular immune responses to mice subcutaneously immunized with ovalbumin (OVA) were examined. ICR mice were immunized with OVA 100 microg alone, the mixture of OVA 100 microg and aluminoid 2 mg, or mixture of OVA 100 microg and PNS 50, 100, or 200 microg on the first and fifteenth day. Two weeks later (d 28), antigen-specific antibody in serum and concanavalin A (Con A)-, pokeweed (PWM)-, and phytohaemagglutinin (PHA)-stimulated splenocyte proliferation were investigated. Haemolytic percents of PNS-treated red blood cell were 11.6 % and 3.6 % at concentrations of 500 and 250 mg/L, respectively. Con A-, PWM- and PHA-stimulated splenocyte proliferation in the mice immunized with OVA/PNS (100 microg) was higher than that in the OVA control group (P<0.01). Mice immunized with OVA and PNS (50, 100, 200 microg) showed significantly higher serum OVA-specific IgG antibody titers (P<0.01) in comparison with the control group that received OVA alone. PNS possesses immunologic adjuvant activities and low-haemolytic effect.