Objective      To explore the changes of positive and negative emotions of the Medical Contingent of the Chinese PLA to Liberia at different stages.        Methods      Positive and negative affect scale (PANAS) was employed on 138 members of the team at different stages

that is

recruitment

training

early period of arriving

and end period of mission. Their emotional changes were statistically analyzed by SPSS 18 Software.        Results      ①Their scores of positive affect were significantly different among different stages (P0.01)

but those of negative affect were not (P0.05). Their scores of positive affect were significantly higher than those of negative affect (P0.01). ② Significant differences were seen in the positive and negative affect scores in the females at different stages (P0.05

P0.01)

and in the positive affect scores in the males at different stages (P0.05). The scores of negative affect in the males were significantly lower than those in the females (P0.01). ③ Besides the doctors

the positive score of the other members were significantly different at different stages (P0.05). Significant difference was also seen in all the members at the recruitment stage (P0.05). ④The positive and negative affect scores of officers and the negative affect score of soldiers were significantly different at different stages (P0.05

0.01). The negative affect scores was significantly higher in the officers than the soldiers at the recruitment and training stages (P0.01).       Conclusion      The members of the Medical Contingent of the Chinese PLA to Liberia have mainly positive affect. Their scores of positive and negative affect are different at 4 stages and among different members.