Thats what the variables mean:
Com-whether the viewed symbol is inside a comment.
j- number of opening brackets reduced by the number of closing
brackets (brackets in comments dont count)
sk-whether the previos symbol was '('
zv-whether the previos symbol was '*'
=-=-==-=-=-=-=-=--=-
Program acm_1027; {D++}
Var A            :array [1..10000] of char;
    i,j,k,l      :integer;
    com,Form,Ans :boolean;
    sk,zv        :boolean;
    c            :char;

Function Bad(x:char):boolean;
var an:boolean;
Begin
  an:=true;
  If x='=' then an:=false;
  If x='+' then an:=false;
  If x='-' then an:=false;
  If x='*' then an:=false;
  If x='/' then an:=false;
  If x='(' then an:=false;
  If x=')' then an:=false;
  If x=#13 then an:=false;
  If x=#10 then an:=false;
  If (x>='0')and(x<='9') then an:=false;
  bad:=an;
End;

Begin
  ans:=true;

  i:=0; c:=' ';
  While (Not Eof) Do
  Begin
    Inc(i);
    Read(A[i]);
  End;
  l:=i;

  j:=0;
  Com:=False; Form:=False; zv:=false; sk:=false;
  For i:=1 to L do
  Begin
    If (A[i]=')') and (not com) then Dec(j);
    If (A[i]=')')and(zv) then com:=false;
    If (A[i]='*')and(sk) then com:=true;
    If (sk) and (not com) then Inc(j);

    If A[i]='*' then zv:=true Else zv:=false;
    If A[i]='(' then sk:=true Else sk:=false;

    If j<0 then ans:=false;
    If (j>0)and(not com)and(Bad(A[i])) then ans:=false;
  End;
  if (j>0)or(com) then ans:=false;
  If Ans then writeln('YES') Else writeln('NO');
End.

Try this test

((*)()()()()()()()()())))))))((((((*)()())

it is correct (YES), but your program returns NO, it thinks that
(*) is opening and closing comment simultaneously;

by the way the test
(*)
is ambiguous - it could be YES, if you consider it as an arithmetical
expression, or it could be NO, if you consider it as an unclosed
comment; my program gives NO (it got AC), yours YES, so I reckon that
(* is with higher priority than (

Good luck.

What's wrong with my program?
I tried all the testdata such as
(*) ->NO
()  ->YES
(()) ->YES
and yours
((*)()()()()()()()()())))))))((((((*)()()) ->YES

And my program still got WA,I don't why.

Could you help me?

const
  MaxSize=10005;

var
  word:array[1..MaxSize] of char;
  Top,Cur:integer;
  C:char;
  Error:boolean;


procedure comment;
var
  b:boolean;
begin
  b:=true;
  inc(cur);
  while (cur<top) and b do
  begin
    if (word[cur]='*') and (word[Cur+1]=')') then b:=false
     else inc(cur);
  end;
  if not b then inc(cur) else error:=true;
end;

procedure expression;
var
  b:boolean;
  T:integer;
begin
  inc(Cur);
  if (Cur>Top) then begin Error:=true; exit; end;
  //if (word[Cur]=')') then begin error:=true; exit; end;
  if word[Cur]='*' then begin Comment; exit; end;
  b:=false;  T:=1;
  while (Not error) and (Cur<=Top) and (T>0) and
    (word[Cur] in ['+','-','*','/','0'..'9','(',')','=']) do
  begin
    if (word[cur]='(') and (word[cur+1]<>'*') then begin b:=true;
T:=T+1; end;
    if (word[cur]<>'(') and (word[cur]<>')') then b:=true;
    if (word[Cur]=')') then T:=T-1;
    if (word[Cur]='(') and (word[Cur+1]='*') then begin inc(cur);
comment; end;
    if T<>0 then inc(cur);
  end;
  if T<>0 then error:=true;
  //if not b then error:=true;

end;

begin

  Top:=0;
  read(c);
  while not eof do
  begin
    if (ord(c)<>13) and (ord(C)<>10) and (ord(c)<>0) then
    begin
      inc(Top);
      word[top]:=c;
    end;
    read(c);
  end;
  Cur:=1; Error:=false;
  Word[Top+1]:=' ';
  while (Not Error) and (Cur<=Top) do
  begin
    if word[Cur]='(' then Expression
      else
        if word[Cur]=')' then error:=true;
    inc(Cur);
  end;
  if Not error then writeln('YES')
    else writeln('NO');
  end.