We study the boundary string field thoery(BSFT) actions by using 
an analytic continuation in momentum space. 
We compute various two- and three- point functions for 
some low-lying excitations including massive states on BPS/non-BPS D-branes. 
Though inclusion of the massive modes has been thought difficult 
because of the non-renormalizability in string sigma models, we overcome 
this by adopting general off-shell momenta and the analytic continuation. 
We also discuss the c=1 matrix model using the BSFT.