There are two main origins of textual errors in early quartos and the First Folio of Shakespeare: scribes and printing houses. To discover these two kinds of errors and to remove them is to establish Shakespeare`s text. What I propose to do in this writing is to discuss (1) origins of textual errors and corruptions, (2) some principles and means for correcting these errors and corruptions, (3) analytical bibliography and its contributions to the establishment of Shakespeare``s text, and (4) some important practices of 16th-and 17th-century English printing houses which have important bearings on the transmission of Shakespeare`s text such as stop-press correction and casting-off copy. Two things are suggested as means to correct textual errors and corruptions. One is documentary evidence which is given by the equally authoritative corresponding text, and the other emendation. Documentary evidence enables us to substitute authorial readings whereas emendation aims at substituting readings as close to inferential authorial readings as possible. It is extremely difficult to produce good emendations. Greg`s warning can serve to prevent bad emendations from being produced: ``no emendation can be, or ought to be, considered in vacuo, but that criticism must always proceed in relation to what we know, or what we surmise, respecting the history of the text.`` Analytical bibliography is an indispensable tool of textual criticism; i.e. the task of establishing Shakespeare`s text. By analysing books as material objects, it seeks to discover all the demonstrable truths about the transmission of texts and about every process of bookmaking from papermaking to human agents involved like compositors, press-correctors, press-men, and bookbinders. The finest triumph that analytical bibliography has so far achieved is the demonstration that six compositors worked for the First Folio of Shakespeare and which part each of them undertook, thus revealing spelling-preferences or habits and reliability of each of them. Compositor B, for instance, introduced a new error in every 15 or 16 lines he composed. This means we can emend him more freely than Compositor A who made an error in every 80 lines. In conclusion, there is no denying that analytical bibliography is indispensable for the task of establishing literary texts in general and Shakespeare`s text in particular.