Objective To research the possible mechanism of safflower extract for steroid-induced avascular necrosis.Methods Forty adult New Zealand white rabbits were randomized into the normal control group

model control group

core decompression group

normal saline+core decompression group and safflower extract+core decompression group

with 8in each.The models of steroid-induced avascular necrosis were established in all groups except the normal control group.There was no treatment in the normal control group and model control group after modeling.The core decompression group was given the core decompression.The normal saline+core decompression group was given normal saline and core decompression.The safflower extract+core decompression group was given 7.2mg/kg safflower yellow A and core decompression.The rabbits were sacrificed one week later.The femoral head in the affected side was removed and the expressions of ERK

JNK and P38were detected with Western Blotting.Results Comparing with the normal control group

the expressions of ERK1and ERK2were significantly decreased but the expressions of JNK and P38were significantly increased in the model control group（P<0.05）.Comparing with the model control group

the expressions of ERK1and ERK2 were significantly increased but the expressions of JNK and P38were significantly decreased in the core decompression group

normal saline+core decompression group and safflower extract+ core decompression group（P<0.05）.Comparing with the core decompression group

the expressions of ERK1and ERK2were significantly increased but the expressions of JNK and P38were significantly decreased in the safflower extract+ core decompression group（P<0.05）.Conclusion Safflower extract can reduce the damage and promote the repair of steroid-induced avascular necrosis by activating the mitogen-activated protein kinase pathway

increasing the phosphorylation level of ERK

reducing the phosphorylation levels of JNK and P38and promoting cell proliferation and differentiation and inhibiting cell apoptosis of femoral intramedullary.