  In this paper we study the protocol implementation and property analysis for
several practical quantum secret sharing (QSS) schemes with continuous variable
graph state (CVGS). For each QSS scheme, an implementation protocol is designed
according to its secret and communication channel types. The estimation error
is derived explicitly, which facilitates the unbiased estimation and error
variance minimization. It turns out that only under infinite squeezing can the
secret be perfectly reconstructed. Furthermore, we derive the condition for QSS
threshold protocol on a weighted CVGS. Under certain conditions, the perfect
reconstruction of the secret for two non-cooperative groups is exclusive, i.e.
if one group gets the secret perfectly, the other group cannot get any
information about the secret.
