This article presents a sketch grammar of Lhagang Tibetan, a dialect of Minyag Rabgang Khams spoken in Tagong Village, Tagong Town, Kangding Municipality, Ganzi Prefecture, Sichuan Province, China. This sketch grammar deals with a variety of Minyag Rabgang Khams, so-called Lhagang-B, transmittetd by the earliest sedentary Tibetans. It contains sound system and description(Section 2), noun phrase (Section 3), verb predicate (Section 4), and sentence construction(Section 5). Section 3 noun phrase is divided into ten subsections: basic structure of the noun phrase (3.1), nouns (3.2), pronouns (3.3), interrogative words (3.4), nominalisers (3.5), grammaticalisation of position nouns (3.6), numbers (3.7), case marking system (3.8), adjectives as a modifier (3.9), and topic marker (3.10). Section 4 verb predicate is divided into eight subsections: basic structure of the verb predicate (4.1), copulative and existential verbs (4.2), general verb stems (4.3), adjectives as a predicate (4.4), prefixes (4.5), suffixes (4.6), verb concatination (4.7), and verbal phrase concordance (4.8). Section 5 sentence construction is explained in variation of sentences (5.1), types of sentence (5.2), sentence embedding (5.3), and complex sentences (5.4).Even though this article merely provides an essence of grammatical aspects of Lhagang Tibetan, it will be worth recording a traditional vernacular of Khams in Lhagang before it changes because of intense language contact.