diff --git a/lib/clientsidescripts.js b/lib/clientsidescripts.js
index ad795ec51..40f9a3704 100644
--- a/lib/clientsidescripts.js
+++ b/lib/clientsidescripts.js
@@ -704,6 +704,60 @@ functions.findByCssContainingText = function(cssSelector, searchText, using) {
   return matches;
 };
 
+/**
+ * Find an element throughout the Shadow DOM by extended css selector.
+ * In order to go into the shadow tree of the element, a special selector `::sr` is used.
+ * As compatible with both Shadow DOM v1 and prior specification, `::sr` will be ignored
+ * for the browser with no support of Shadow DOM, so the result will be same.
+ *
+ * Usage:
+ *   element(by.shadowRoot('#outer #inner'))          <=>  $('#outer #inner')
+ *   element(by.shadowRoot('#outer::sr #inner'))      <=>  $('#outer').shadowRoot.$('#inner')
+ *   element.all(by.shadowRoot('#outer .inner'))      <=>  $$('#outer .inner')
+ *   element.all(by.shadowRoot('#outer::sr .inner'))  <=>  $$('#outer').shadowRoot.$$('.inner')
+ *   outer.element(by.shadowRoot('#inner'))           <=>  outer.$('#inner')
+ *   outer.element(by.shadowRoot('::sr #inner'))      <=>  outer.shadowRoot.$('#inner')
+ *   outer.all(by.shadowRoot('.inner'))               <=>  outer.$$('.inner')
+ *   outer.all(by.shadowRoot('::sr .inner'))          <=>  outer.shadowRoot.$$('.inner')
+ *
+ * @param {string} selector An extended css selector, each `::sr` in which
+ *   will go into the shadow root of the element.
+ * @param {Element} using The scope of the search.
+ *
+ * @return {Array.<Element>} The matching elements.
+ */
+functions.findByShadowRoot = function(selector, using) {
+  var selectors = selector.split('::sr');
+  if (selectors.length === 0) {
+      return [];
+  }
+
+  var shadowDomInUse = (document.head.createShadowRoot || document.head.attachShadow);
+  var getShadowRoot  = function (el) {
+    return ((el && shadowDomInUse) ? el.shadowRoot : el);
+  };
+  var findAllMatches = function (selector /*string*/, targets /*array*/, firstTry /*boolean*/) {
+      var scope, i, matches = [];
+      for (i = 0; i < targets.length; ++i) {
+          scope = (firstTry) ? targets[i] : getShadowRoot(targets[i]);
+          if (scope) {
+              if (selector === '') {
+                  matches.push(scope);
+              } else {
+                  Array.prototype.push.apply(matches, scope.querySelectorAll(selector));
+              }
+          }
+      }
+      return matches;
+  };
+
+  var matches = findAllMatches(selectors.shift().trim(), [using || document], true);
+  while (selectors.length > 0 && matches.length > 0) {
+      matches = findAllMatches(selectors.shift().trim(), matches, false);
+  }
+  return matches;
+};
+
 /**
  * Tests whether the angular global variable is present on a page. Retries
  * in case the page is just loading slowly.
diff --git a/lib/locators.ts b/lib/locators.ts
index f6852ea02..da8d11d47 100644
--- a/lib/locators.ts
+++ b/lib/locators.ts
@@ -491,4 +491,41 @@ export class ProtractorBy extends WebdriverBy {
     // When that is supported, switch it here.
     return By.css('* /deep/ ' + selector);
   };
+
+  /**
+   * Find an element throughout the Shadow DOM by extended css selector.
+   * In order to go into the shadow tree of the element, use a special selector `::sr`.
+   * As compatible with both Shadow DOM v1 and prior specification, `::sr` will be ignored
+   * for the browser with no support of Shadow DOM, so the result will be same.
+   *
+   * @alias by.shadowRoot(selector)
+   * @view
+   * <div>
+   *   <span id="outerspan">
+   *   <"shadow tree">
+   *     <span id="span1"></span>
+   *     <"shadow tree">
+   *       <span id="span2"></span>
+   *     </>
+   *   </>
+   * </div>
+   * @example
+   * var span1 = element(by.shadowRoot('#outerspan::sr #span1'));
+   * var span2 = element(by.shadowRoot('#outerspan::sr #span1::sr #span2'));
+   *
+   * @param {string} selector an extended css selector, each `::sr` in which will go into the shadow root of the element
+   * @returns {Locator} location strategy
+   */
+  shadowRoot(selector: string): Locator {
+    return {
+      findElementsOverride: (driver: WebDriver, using: WebElement, rootSelector: string):
+                                wdpromise.Promise<WebElement[]> => {
+        return driver.findElements(
+            By.js(clientSideScripts.findByShadowRoot, selector, using, rootSelector));
+      },
+      toString: (): string => {
+        return 'by.shadowRoot("' + selector + '")';
+      }
+    };
+  };
 }
diff --git a/spec/basic/locators_spec.js b/spec/basic/locators_spec.js
index 0f370b00b..84f796517 100644
--- a/spec/basic/locators_spec.js
+++ b/spec/basic/locators_spec.js
@@ -414,6 +414,27 @@ describe('locators', function() {
     });
   });
 
+  describe('by shadowRoot', function() {
+    beforeEach(function() {
+      browser.get('index.html#/shadow');
+    });
+
+    it('should find items inside the shadow DOM', function() {
+      var parent = element(by.shadowRoot('#innerDiv::sr #parentDiv'));
+      var parentHeading = parent.element(by.shadowRoot('.parentshadowheading'));
+      var youngerChildHeading = parent.element(by.shadowRoot('::sr .youngershadowheading'));
+
+      expect(parentHeading.isPresent()).toBe(true);
+      expect(youngerChildHeading.isPresent()).toBe(true);
+
+      expect(parentHeading.getText()).toEqual('Parent');
+      expect(youngerChildHeading.getText()).toEqual('Younger Child');
+
+      expect(element(by.shadowRoot('.originalcontent')).getText())
+          .toEqual('original content');
+    });
+  });
+
   it('should determine if an element is present', function() {
     expect(browser.isElementPresent(by.binding('greet'))).toBe(true);
     expect(browser.isElementPresent(by.binding('nopenopenope'))).toBe(false);