  We present the results of comparative study of amplitude calibrations for
East-Asia VLBI Network (EAVN) at 22 and 43 GHz using two different methods of
an "a-priori" and a "template spectrum", particularly on lower declination
sources. Using observational data sets of early EAVN observations, we
investigated the elevation-dependence of the gain values at seven stations of
the KaVA (KVN and VERA Array) and three additional telescopes in Japan
(Takahagi 32m, Yamaguchi 32m and Nobeyama 45m). By comparing the independently
obtained gain values based on these two methods, we found that the gain values
from each method were consistent within 10% at elevations higher than 10
degree. We also found that the total flux densities of two images produced from
the different amplitude calibrations were in agreement within 10% at both 22
and 43 GHz. By using the template spectrum method, furthermore, the additional
radio telescopes can participate in the KaVA (i.e. EAVN) so that it can give a
notable sensitivity increase. Therefore, our results will constrain the
detailed conditions to reliably measure the VLBI amplitude using EAVN and give
a potential to extend possible telescopes comprising EAVN.
