Objective To identify the metabolite levels and to study the potential effects of risporidone tablets on prefrontal lobe and thalamus in male first-episode schizophrenia by proton magnetic resonance spectroscopy (1H-MRS).Methods Twenty-two male first-episode schizophrenics were examined at prefrontal lobe and thalamus by multi-voxel 1H-MRS before and after 8 weeks' risperidone tablets treatment,and 30 normal controls were assessed once.The patients were also received positive and negative syndrome scale(PANSS) and Wisconsin card sorting test (WCST) before and after treatment.The N-aeetylaspartate ( NAA ),Choline-congtaining compounds (Cho),and Creatine compounds (Cr) were measured and the ratios of NAA/Cr,Cho/Cr were determined.Results On left prefrontal lobe and left thalamus,the NAA/Cr ratio in patients before treatment demonstrated lower than those in normal controls ( ( 1.37 ± 0.33 ) vs ( 1.61 ± 0.38 ),t =2.57,P ＜ 0.05 ; ( 1.46 ± 0.35 ) vs ( 1.71 ± 0.38 ),t =2.36,P ＜ 0.05 ).There were no significant differences in both the ratios of NAA/Cr and Cho/Cr between pre- and post-treatment (P＞0.05 ).The changes of NAA/Cr on left prefrontal lobe post-treatment were negatively related with the alterations of the total score of PANSS ( r =- 0.46,P ＜ 0.05 ),the score of negative symptoms ( r =- 0.48,P ＜ 0.05 ),the responses errors ( r =- 0.42,P ＜ 0.05 ) and the porseverative errors ( r =- 0.40,P ＜ 0.05 ),meanwhile,positively related with the alterations of the categories completed ( r =0.44,P ＜0.05 ) and the conceptual level responses ( r =0.42,P ＜ 0.05 ).Conclusions Abnormalities in neuronal function and/or integrity presented on prefrontal lobe and thalamus maybe exist in male first-episode schizophrenics.Short-term antipsvchotic treatment with risperidone tablets may have no effects on measures of prefrontal lobe and thalamus.