Thank you for your reply.

Reiner Steib <reinersteib+gmane@imap.cc> writes:
> Could you try the following patch, please?

`spam-check-spamassassin-headers' works fine, however
`spam-extra-header-to-number' doesn't.

spamassasin add header like this:
| X-Spam-Status: Yes, score=13.1 required=5.0 tests=DNS_FROM_RFC_ABUSE,
| 	DNS_FROM_RFC_WHOIS,FORGED_YAHOO_RCVD,MISSING_SUBJECT,NO_REAL_NAME,
| 	UNDISC_RECIPS autolearn=disabled version=3.0.3

Score always becomes 0 at (string-to-number (gnus-replace-in-string
... )), because "Yes" or "No" flag exist before score=xxx.

When I changed spam.el as attached, the displayed score is corrected.

Best regards,
-- 
IRIE Tetsuya