Oracle instant client is installed in Linux on the PL/SQL Dev Virtual Machine and Oracle is installed. Since PL/SQL Developer is used in Windows physical machines to connect to Oracle on the virtual machine, but I don't want to reinstall Oracle on the Physical Machine (too big, no more =. = ). Therefore, Oracle Instant Client is used. Okay, I don't have to talk about it anymore. Step 1: configure the listener in Linux. Listener. the ora file content is as follows # listener. ora Network Configuration File:/u01/app/oracle/product/10.2.0/db_1/network/admin/listener. ora # Generated by Oracle configuration tools. SID_LIST_LISTENER = www.2cto.com (SID_LIST = (SID_DESC = (SID_NAME = PLSExtProc) (ORACLE_HOME =/u01/app/oracle/product/10.2.0/db_1) (PROGRAM = extproc )) (SID_DESC = (GLOBAL_DBNAME = wiseman) (ORACLE_HOME =/u01/app/oracle/product/10.2.0/db_1) (SID_NAME = wiseman) LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = 192.168.0.99) (PORT = 1521 ))) (DESCRIPTION = (ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC0) www.2cto.com) Note: SID_name must be the same case as SID in Linux. I have lower-case 2, and then configured Windows. http://www.oracle.com/technetwork/topics/winsoft-085727.html Download the following instantclient-basic-nt-11.2.0.3.0.zip (my 32-bit system), decompress it to C: \ Oracle \ instantclient_11_2, and then download tnsnames. copy ora to C: \ Oracle \ instantclient_11_2 \ network \ admin. Content: GGDB = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = 192.168.0.99) (PORT = 1521) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = WISEMAN) 3. Finally, set PL/SQL Developer, tool --> to change the preference to the following content. Restart PL/SQL Developer and log on again. Supplement: instantclient-sqlplus-nt-11.2.0.3.0.zip can be downloaded on a webpage without built-in SQL * plus. After the download, www.2cto.com configures the windows system variables. NLS_lANG = SIMPLIFIED CHINESE_CHINA.ZHS16GBKTNS_ADMIN = C: \ Oracle \ instantclient_11_2Path = C: \ Oracle \ instantclient_11_2 now you can use sqlplus system/oracle @ GGDB to connect. Author wise_man