This paper seeks to establish a chronology of the production period of local porcelains from the mid-Joseon dynasty based on a stylistic analysis of their forms, and examines the distinct features and changes according to the production periods of local porcelains. Mid-Joseon was a transitional period in which porcelain works displayed features of the preceding and subsequent periods. As such, it is the most suitable period from which to attempt an understanding of the development of local porcelains of the Joseon dynasty. The local porcelains have not been unveiled until today, as previous studies tended to focus on porcelains produced for the Royal Court and the government. Scholars are, however, now increasing their investigations of local porcelains, whose production sites have been found in considerable numbers throughout the country, including the abundant remains of kilns. Studies of local porcelains enable researchers to suggest a balanced perspective of the history of Joseon porcelain and ascertain the correct positioning of local porcelain. The kiln sites that produced mid-Joseon local porcelain, identified by excavations and surface surveys, are evenly distributed throughout the nation. In that period, many kinds of wares had been destroyed during the Imjin Waeran (Japanese invasion of Korea in 1592) and the Byeongja Horan (invasion of Korea by the Ching dynasty in 1636) and the demand for porcelains increased it gradually replacing metal wares. Furthermore, as the commercial population grew so did the production and circulation of the porcelain. It is believed that local porcelain kilns outnumbered royal ones because of the short operation period of local kilns. In this paper, porcelain wares from eleven local kilns, whose reports had already been published, are examined, and stylistic analyses of various forms, including large bowls (沙鉢), medium-sized bowls (大?), dishes (?匙) and small bowls (盞) are conducted, accounting for more than 96% of all the porcelain wares. The analises were conducted based on the contours of the objects'outer wall, the shape of the rim, the presence of an inner bottom circle and its sizes, and the shapes of the foot. Firstly, of the large, medium, and small bowls and the dishes, the most commonly occurring style of each form were named the 'major form'while the other forms were grouped as the 'minor form.'The 'major form'represents the general form of the contemporary porcelain produced by the kilns. The 'minor form'is either a 'transitional form,'which is reminiscent if the forms from the preceding period, or a newly developed form, or 'indicator form.'Local kilns with a similar 'major form'are grouped into three Periods: An 'indicator form'such as the dish with a flat rim of Period Ⅰ, dish-3 with a straight rim sharply edging outfrom the upper body of Period Ⅱ, and the ritual dish of Period Ⅲ could serve as significant references in attempting to determine the operating period of the kilns. Local porcelains decorated with an iron-brown and cobalt blue under-glaze have only been unearthed from the kilns of Periods Ⅱ and Ⅲ. It appears that the development of local porcelains began with undecorated pure white porcelain and later developed into porcelain featuring an iron-brown and cobalt-blue under-glaze paintings. In the mid- Joseon dynasty, porcelain with an iron-brown under-glaze decoration prevailed throughout the country. Its designs reflected regional characteristics, wit the designs found amongst the adjacent kilns showing a close resemblance. Through comparative investigations with the royal porcelains and other dated remains, this study established the following production periods: Period Ⅰ - late sixteenth to mid-seventeenth centuries; Period Ⅱ - mid-seventeenth to early eighteenth centuries; and Period Ⅲ - early eighteenth to mid-eighteenth centuries. In the course of the investigation, it was revealed that the local porcelains were closely related to the sangbun-yo (kilns in which porcelain objects were loaded one on top of another), which produced objects for government offices and the Royal Court. Until the late seventeenth century, local potters were employed in shifts at the royal kilns, so local porcelains were under the continuous influence of royal porcelains. The structure of the local kilns also showed variations. The structure of the kilns in Period I had both the features of the earlier and later kilns, while Period II showed the typical structure of the mid-Joseon dynasty. Lastly, the kilns of Period Ⅲ presented certain transitional characteristics, whereby the features of the mid and latter Joseon kilns coexisted. As has been shown, the structures of the local kilns corresponded with the stylistic changes of local porcelain and varied according to the operating periods. In conclusion, the form of local porcelains during the mid-Joseon dynasty developed according to its operating periods under the influence of royal porcelains. The designs, however, were irrelevant to the royal wares and the periodic changes. It was rather the regional characteristics. Further investigations and accumulations of research references could advance any detailed studies of the regional features of local wares and their production periods. The in-depth examination of the relationship between royal and local porcelains remains as a prospective future research.