i have Solve the problem by myself.
i find that,the color and size of the bullets are the same to the last "\r",so i remeber the position ,and find the first "\r" from the position to set it color and size.
if(imInfo.iLastStart!=0)
{
SetSel(imInfo.iLastStart,imInfo.iLastStart+1);
SetParaFormat(pf2);
FINDTEXTEXW ft; ft.chrg.cpMin = imInfo.iLastStart;
ft.chrg.cpMax = -1;
ft.lpstrText=_T("\r");
long n = FindText(FR_DOWN,ft);
if(n!=-1)
{
SetSel( n,n+1);
SetWordCharFormat( cfPoint );
}
imInfo.iLastStart = 0;
}