using DocumentFormat.OpenXml.Wordprocessing;
using DocumentFormat.OpenXml.Packaging;
using (var document = WordprocessingDocument.Open(@"Your.docx", false))
{
var main = document.MainDocumentPart;
var fonts = main.FontTablePart;
var styles = main.StyleDefinitionsPart;
var effects = main.StylesWithEffectsPart;
var doc = main.Document;
var body = doc.Body;
foreach (Paragraph para in body.Descendants<Paragraph>()
.Where(e => e.ParagraphProperties != null&& e.ParagraphProperties.ParagraphStyleId != null))
Console.WriteLine("Text:{0}->Style name:{1}", para.InnerText, para.ParagraphProperties.ParagraphStyleId.Val);
foreach (Run run in body.Descendants<Run>()
.Where(r => r.RunProperties != null && r.RunProperties.RunStyle != null))
Console.WriteLine("Text: {0}->Run style: {1}", run.InnerText, run.RunProperties.RunStyle.Val );
}