Hi : Thanks for you answer! I have tried it for several hours, and found it only NOT happened when rowsourcetype is 'Value'. for 'field', 'SQL statement' and etc. it will happened to 253th item, 509th(253+256), 765th(253+256+256),.... I don't know if this bug is now in microsoft/vfp known bug list yet, and don't know when microsoft will correct it. Maybe I need to rewrite my code now! ZhouHang May-28-1997