Recen t ly , GILMAN et al. (~) h a v e p roposed t h a t p o m e r o n e x c h a n g e t e r m s conserve s channe l heliei t ies. I n o rde r to e x a m i n e th i s proposal , HARAnI a n d ZARMI (*) h a v e ana ly sed t h e p ion -nuc leon s c a t t e r i n g ampl i t ude . In t h i s p a p e r we s t u d y t h e p rope r t i e s of t he p o m e r o n e x c h a n g e a m p l i t u d e f rom a d i f fe rent v iewpoin t . I t seems t h a t t h e p o m e r o n t e r m s are respons ib le for t h e d i f f rac t ion peaks in elast ic s c a t t e r i n g a t h i g h ene rgy a n d dif f ract ion s c a t t e r i n g in t he f o r w a r d d i rec t ion m a i n l y comes f rom t h e sp in-nonf l ip ampl i t ude . On t h e basis of these facts , we wish to p ropose t h a t t h e r e is no s channe l spin-fl ip a m p l i t u d e in t h e p o m e r o n t e rm. Th i s p roposa l for t he p rope r t i e s of t h e p o m e r o n e x c h a n g e a m p l i t u d e is qu i te d i f fe rent f rom t h a t of GILMAN et al. (*). A n d we sugges t a m e t h o d to e x a m i n e our proposa l . I t is shown t h a t our p roposa l is cons i s t en t w i t h t he phase sh i f t ana lys is of meson -nuc l eon sca t t e r ing . The m e t h o d enables us to resolve t h e a m b i g u i t y for phase sh i f t ana lys i s a n d to e x a m i n e t h e ex is tence of t h e Z*. As is well known, t h e a m p l i t u d e ](0) for T:-JW (K-W) s c a t t e r i n g is expressed b y