A computer program (Q-test) was used to evaluate the combined toxic effects of nerve agent GF and its combined form with sarin (GB/GF) in mice. Efficacy of Jielin Injection, the 2-PAM-containing antidote used successfully in China for the treatment of organophosphate pesticide poisoning, was also evaluated and compared with HI-6 against single and combined poisonings. The two agents were basically additive in toxicity when combined. However, toxic signs (convulsions) appeared later in combined poisoning than after exposure to each agent alone. The protective ratio of Jielin Injection against GF poisoning was low but significantly higher when against poisoning by GB or combined agent. When HI-6 was substituted for 2-PAM, the antidote was more effective against poisoning by both single and combined agents. Results of in vitro reactivation of GF-inhibited human erythrocyte acetylcholinesterase by these oximes agreed with the in vivo antidotal efficacy.