In th is paper, w e develop the respon se su rface equat ion s fo r the crit ical value fo r co in tegrat ion test in sm all samp le u singMon te Carlo sim u lat ion. The sim u lat ion resu lt s indicate that the crit ical values are related w ith the num ber of the samp le data as w ell as the lagged o rder fo r co in tegrat ion test. W e also p resen t an emp irical analysis fo r the food con sump t ion of the Ch inese residen t s in cit ies and tow n s.