diff --git a/How-to-install.md b/How-to-install.md
new file mode 100644
index 0000000..35b33f2
--- /dev/null
+++ b/How-to-install.md
@@ -0,0 +1,59 @@
+## 1. Install from web: https://get.acme.sh
+
+Install https://github.com/Neilpang/acme.sh
+
+```
+curl https://get.acme.sh | sh
+
+```
+
+or
+
+```
+wget -O -  https://get.acme.sh | sh
+```
+
+## 2. Or, install from Git hub:
+
+```
+curl https://raw.githubusercontent.com/Neilpang/acme.sh/master/acme.sh | INSTALLONLINE=1  sh
+```
+
+or:
+```
+wget -O -  https://raw.githubusercontent.com/Neilpang/acme.sh/master/acme.sh | INSTALLONLINE=1  sh
+```
+
+
+## 3. Or, git clone and install:
+
+```
+git clone https://github.com/Neilpang/acme.sh.git
+cd acme.sh
+./acme.sh --install
+```
+
+
+## 4. Advanced installation
+
+```
+git clone https://github.com/Neilpang/acme.sh.git
+cd acme.sh
+./acme.sh --install  \
+--home ~/myacme \
+--certhome  ~/mycerts \
+--accountemail  "hi@acme.sh" \
+--accountkey  ~/myaccount.key \
+--accountconf ~/myaccount.conf \
+--useragent  "this is my client."
+```
+
+Explanations :
+
+- `--home` is a customized dir to install `acme.sh` in.  By default, it installs into `~/.acme.sh` 
+- `--certhome` is a customized dir to save the certs you issue.  By default, it saves he certs in `--home`.
+- `--accountemail` is the email used to register account to Let's Encrypt,  you will receive renewal notice email here. Default is empty.
+- `--accountkey` is the file saving your account private key.  By default it's saved in `--home`.
+- `--useragent`  is the user-agent header value used to send to Let's Encrypt.
+
+