diff --git a/client.go b/client.go
index 99cf62a..47cde6b 100644
--- a/client.go
+++ b/client.go
@@ -2,26 +2,20 @@ package growi_client
 
 import (
 	"encoding/json"
-	"errors"
 	"github.com/ictsc/growi_client/entity"
-	"golang.org/x/net/html"
 	"io/ioutil"
 	"net/http"
 	"net/http/cookiejar"
 	"net/url"
-	"strings"
 )
 
 type Client interface {
-	Init() error
 	GetSubordinatedPage(path string) ([]entity.SubordinatedPage, error)
 	GetPage(path string) (*entity.Page, error)
 }
 
 type GrowiClientOption struct {
 	URL         *url.URL
-	Username    string
-	Password    string
 	AccessToken string
 }
 
@@ -34,20 +28,12 @@ var client *http.Client
 
 var _ Client = (*GrowiClient)(nil)
 
-func (c *GrowiClient) Init() error {
+func NewGrowiClient(option *GrowiClientOption) *GrowiClient {
 	client = &http.Client{}
-	client.Jar = c.Jar
 
-	csrfToken, err := getCsrfToken(*c.Option.URL, *client)
-	if err != nil {
-		return errors.New("failed to get csrf token")
-	}
-	err = doLogin(*c.Option.URL, *client, c.Option.Username, c.Option.Password, csrfToken)
-	if err != nil {
-		return errors.New("failed to login")
+	return &GrowiClient{
+		Option: option,
 	}
-
-	return nil
 }
 
 type SubordinatedPagesResponse struct {
@@ -127,70 +113,3 @@ func (c *GrowiClient) GetPage(path string) (*entity.Page, error) {
 
 	return &pageResponse.Page, nil
 }
-
-// getCsrfToken は CSRF Token を取得する
-func getCsrfToken(u url.URL, client http.Client) (string, error) {
-	u.Path = "/login"
-
-	req, err := http.NewRequest("GET", u.String(), nil)
-	if err != nil {
-		return "", err
-	}
-
-	resp, err := client.Do(req)
-	if err != nil {
-		return "", err
-	}
-	defer resp.Body.Close()
-
-	body, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return "", err
-	}
-
-	node, err := html.Parse(strings.NewReader(string(body)))
-	if err != nil {
-		return "", err
-	}
-
-	// html > body attr の中から csrfToken を取得
-	for c := node.FirstChild; c != nil; c = c.NextSibling {
-		if c.Type == html.ElementNode && c.Data == "html" {
-			for d := c.FirstChild; d != nil; d = d.NextSibling {
-				if d.Data == "body" {
-					for _, attr := range d.Attr {
-						if attr.Key == "data-csrftoken" {
-							return attr.Val, nil
-						}
-					}
-				}
-			}
-		}
-	}
-
-	return "", nil
-}
-
-func doLogin(u url.URL, client http.Client, username string, password string, csrfToken string) error {
-	u.Path = "/login"
-
-	form := url.Values{}
-	form.Add("loginForm[username]", username)
-	form.Add("loginForm[password]", password)
-	form.Add("_csrf", csrfToken)
-
-	req, err := http.NewRequest("POST", u.String(), strings.NewReader(form.Encode()))
-	if err != nil {
-		return err
-	}
-
-	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-
-	resp, err := client.Do(req)
-	if err != nil {
-		return err
-	}
-	defer resp.Body.Close()
-
-	return nil
-}