We consider the following perturbed polyharmonic operator L(x, D) of order 2m defined in a bounded domain Ω ⊂ R n , n ≥ 3 with smooth boundary, aswhere A is a symmetric 2-tensor field, B and q are vector field and scalar potential respectively. We show that the coefficients A = [A jk ], B = (B j ) and q can be recovered from the associated Dirichletto-Neumann data on the boundary. Note that, this result shows an example of determining higher order (2nd order) symmetric tensor field in the class of inverse boundary value problem.2010 Mathematics Subject Classification. Primary 35R30, 31B20, 31B30, 35J40 .