Pros: Automatic, no additional work on your part.
Cons: All HTML tags are stripped from the summary, and the first 70 words, whether they belong to a heading or to different paragraphs, are all put into one paragraph.
So I fixed it by using manual divider .
User-defined: Manual Summary Splitting
Alternatively, you may add the summary divider where you want to split the article. For org content, use # more where you want to split the article. Content that comes before the summary divider will be used as that content’s summary and stored in the .Summary page variable with all HTML formatting intact.