Let R be a Noetherian ring, M an Artinian R-module, \p∈\CosRM.
Then \cogradeR\p\HomR(R\p,M)=inf{i∣πi(\p,M)>0} and
πi(\p,M)>0⇒\cogradeR\p\HomR(R\p,M)≤i≤\fdR\p\HomR(R\p,M), where πi(\p,M) is the i-th dual
Bass number of M with respect to \p, the integer
\cogradeR\p\HomR(R\p,M) is the common length of any maximal
\HomR(R\p,M)-quasi co-regular sequence contained in \pR\p, and
\fdR\p\HomR(R\p,M) is the flat dimension of R\p-module
\HomR(R\p,M) (Theorem \ref{Thm:Main}). Besides, we also study the
relations among cograde, co-dimension and flat dimension of co-localization
module \HomR(R\p,M).