In this talk, I will give a brief survey on the so-called method of \emph{SP} operators arising from the usual substitution of parameters to transformation formulas of basic hypergeometric series ($q$-series). Some concrete substitution of parameter operators implied by some known and fundamental transformation formulas are given in details, and related applications to the ${}_{r+1}\phi _{r}$ series for $r=1,2,7,9$ are exploited. Some of the most interesting applications are the equivalency of Watson's transformation of ${}_2\phi_1$ series and Weierstrass' theta function identity; a novel representation of very-well-poised ${}_8\phi_7$ series in terms of bilateral ${}_{10}\psi_{10}$; a iterative proof of Bailey's ${}_6\psi_6$ summation formula.

This report is based on the joint works with Dr. Jin Wang.